If you’re weighing classic Reformed covenant theology (Westminster) against Baptist federalism (1689), here are three questions that clarify the differences. Here we unpack each one and include the full King James text of the key passages so you can test the logic yourself—then we add a practical guide to the sacraments: Baptism and the Lord’s Supper.
Classic Reformed covenant theology (Westminster) says there is one Covenant of Grace across redemptive history, administered differently before and after Christ, but always the same in substance (Christ and His saving benefits). That’s why Paul can argue that the way Abraham was justified is the way we are justified—by faith—and why Gentile believers are counted as Abraham’s children.
Galatians 3:7–9, 14, 16, 29 (KJV) 7 Know ye therefore that they which are of faith, the same are the children of Abraham. 8 And the scripture, foreseeing that God would justify the heathen through faith, preached before the gospel unto Abraham, saying, In thee shall all nations be blessed. 9 So then they which be of faith are blessed with faithful Abraham. 14 That the blessing of Abraham might come on the Gentiles through Jesus Christ; that we might receive the promise of the Spirit through faith. 16 Now to Abraham and his seed were the promises made. He saith not, And to seeds, as of many; but as of one, And to thy seed, which is Christ. 29 And if ye be Christ’s, then are ye Abraham’s seed, and heirs according to the promise.
Romans 4:1–5 (KJV) 1 What shall we say then that Abraham our father, as pertaining to the flesh, hath found? 2 For if Abraham were justified by works, he hath whereof to glory; but not before God. 3 For what saith the scripture? Abraham believed God, and it was counted unto him for righteousness. 4 Now to him that worketh is the reward not reckoned of grace, but of debt. 5 But to him that worketh not, but believeth on him that justifieth the ungodly, his faith is counted for righteousness.
Romans 4:9–12 (KJV) 9 Cometh this blessedness then upon the circumcision only, or upon the uncircumcision also? for we say that faith was reckoned to Abraham for righteousness. 10 How was it then reckoned? when he was in circumcision, or in uncircumcision? Not in circumcision, but in uncircumcision. 11 And he received the sign of circumcision, a seal of the righteousness of the faith which he had yet being uncircumcised: that he might be the father of all them that believe, though they be not circumcised; that righteousness might be imputed unto them also: 12 And the father of circumcision to them who are not of the circumcision only, but who also walk in the steps of that faith of our father Abraham, which he had being yet uncircumcised.
Takeaway: Paul grounds Christian salvation in Abraham’s pattern. The substance hasn’t changed (grace through faith); the administration has (from shadow to fullness in Christ). That’s Westminster’s heartbeat.
Baptist federalism, by contrast, argues that Jeremiah 31/Hebrews 8 makes the New Covenant “regenerate-only,” so only those who personally “know the Lord” belong to it and thus receive its sign.
Jeremiah 31:33–34 (KJV) 33 But this shall be the covenant that I will make with the house of Israel; After those days, saith the LORD, I will put my law in their inward parts, and write it in their hearts; and will be their God, and they shall be my people. 34 And they shall teach no more every man his neighbour, and every man his brother, saying, Know the LORD: for they shall all know me, from the least of them unto the greatest of them, saith the LORD: for I will forgive their iniquity, and I will remember their sin no more.
Hebrews 8:10–12 (KJV) 10 For this is the covenant that I will make with the house of Israel after those days, saith the Lord; I will put my laws into their mind, and write them in their hearts: and I will be to them a God, and they shall be to me a people: 11 And they shall not teach every man his neighbour, and every man his brother, saying, Know the Lord: for all shall know me, from the least to the greatest. 12 For I will be merciful to their unrighteousness, and their sins and their iniquities will I remember no more.
Westminster reading: These promises are certainly and effectually true for the elect (the “invisible church”). But until glory, the visible church remains a mixed body (wheat and tares, a net with good and bad). So the New Covenant is new in efficacy and clarity, not a total redefinition of visible membership.
Classic Reformed covenant theology says yes: God’s ordinary way is to gather households, and the visible church therefore includes believers and their children. That’s why Westminster includes the children of believers in the visible church and gives them the covenant sign.
Acts 2:39 (KJV) For the promise is unto you, and to your children, and to all that are afar off, even as many as the Lord our God shall call.
1 Corinthians 7:14 (KJV) For the unbelieving husband is sanctified by the wife, and the unbelieving wife is sanctified by the husband: else were your children unclean; but now are they holy.
Takeaway: Peter reaffirms the you / your children / the nations pattern of Genesis 17, now widened to “all that are afar off.” Paul calls believers’ children holy (set apart). Westminster sees this as warrant for keeping the family shape of the visible church in the New Covenant—with baptism as the covenant sign given to believers and their children.
Westminster argues that baptism succeeds circumcision as the covenant sign of union with Christ and cleansing—so the subjects (believers and their children) remain the same in the visible community, even as the sign changes from blood to water.
Colossians 2:11–12 (KJV) 11 In whom also ye are circumcised with the circumcision made without hands, in putting off the body of the sins of the flesh by the circumcision of Christ: 12 Buried with him in baptism, wherein also ye are risen with him through the faith of the operation of God, who hath raised him from the dead.
Takeaway: Paul links what circumcision signified (heart-renewal) with what baptism signifies (union with Christ’s death and resurrection). The meaning is fulfilled in Christ; the sign changes; the covenantal logic of God claiming believers and their households continues.
Answer these three questions from the classic Reformed compass and you land with Westminster:
That is why Westminster teaches one Covenant of Grace under various administrations, believers and their children as members of the visible church, and baptism as the fitting covenant sign for both.
In Scripture, a sacrament is a God-instituted sign and seal of His covenant grace—exhibiting Christ and confirming His promises to believers.
Romans 4:11 (KJV) And he received the sign of circumcision, a seal of the righteousness of the faith which he had yet being uncircumcised: that he might be the father of all them that believe…
Salvation itself is by grace through faith, not by bare participation in rites:
Ephesians 2:8–9 (KJV) For by grace are ye saved through faith; and that not of yourselves: it is the gift of God: Not of works, lest any man should boast.
Hypothetical: Lydia sits under the Word and receives baptism and the Supper for years, yet never truly trusts Christ. The signs won’t save her by themselves. But when Noah believes the gospel, those same signs become means of grace—the Spirit uses them to strengthen the faith that saves.
Romans 6:3–4 (KJV) Know ye not, that so many of us as were baptized into Jesus Christ were baptized into his death? Therefore we are buried with him by baptism into death: that like as Christ was raised up from the dead by the glory of the Father, even so we also should walk in newness of life.
Titus 3:5 (KJV) Not by works of righteousness which we have done, but according to his mercy he saved us, by the washing of regeneration, and renewing of the Holy Ghost;
1 Peter 3:21 (KJV) The like figure whereunto even baptism doth also now save us (not the putting away of the filth of the flesh, but the answer of a good conscience toward God,) by the resurrection of Jesus Christ:
Colossians 2:11–12 (KJV) (already quoted above)
In short: Baptism visibly preaches the gospel: Christ’s death and resurrection applied to us, cleansing and new life received by faith.
Professing believers (those who receive the Word with faith):
Acts 2:41 (KJV) Then they that gladly received his word were baptized: and the same day there were added unto them about three thousand souls.
Believers and their children (covenant continuity):
Acts 2:39 (KJV) For the promise is unto you, and to your children, and to all that are afar off, even as many as the Lord our God shall call.
1 Corinthians 7:14 (KJV) …else were your children unclean; but now are they holy.
Household pattern:
Acts 16:15 (KJV) And when she was baptized, and her household, she besought us… Acts 16:33 (KJV) And he took them the same hour of the night, and washed their stripes; and was baptized, he and all his, straightway. 1 Corinthians 1:16 (KJV) And I baptized also the household of Stephanas…
Hypotheticals:
Christ’s command:
Matthew 28:19–20 (KJV) Go ye therefore, and teach all nations, baptizing them in the name of the Father, and of the Son, and of the Holy Ghost: Teaching them to observe all things whatsoever I have commanded you…
One baptism (not repeated):
Ephesians 4:5 (KJV) One Lord, one faith, one baptism.
Mode: Scripture does not bind us to a single action. Baptism is rightly administered with water (by pouring, sprinkling, or immersion). Examples of going down to/coming up from water exist:
Acts 8:38–39 (KJV) And he commanded the chariot to stand still: and they went down both into the water, both Philip and the eunuch; and he baptized him. And when they were come up out of the water, the Spirit of the Lord caught away Philip…
And Scripture often speaks of covenant cleansing in sprinkling/pouring imagery tied to the Spirit’s work:
Hebrews 10:22 (KJV) Let us draw near with a true heart in full assurance of faith, having our hearts sprinkled from an evil conscience, and our bodies washed with pure water.
Practical execution (Westminster-shaped):
Who administers? A lawfully called minister of the Word (cf. 1 Cor. 4:1).
When? After credible profession—or for children, upon parental profession with public vows to raise them in the faith.
Where? In the assembly if possible, because baptism admits to the visible church (1 Cor. 12:13).
1 Corinthians 12:13 (KJV) For by one Spirit are we all baptized into one body, whether we be Jews or Gentiles… and have been all made to drink into one Spirit.
Hypotheticals:
Institution:
Luke 22:19–20 (KJV) And he took bread, and gave thanks, and brake it, and gave unto them, saying, This is my body which is given for you: this do in remembrance of me. Likewise also the cup after supper, saying, This cup is the new testament in my blood, which is shed for you.
Communion with Christ and with one another:
1 Corinthians 10:16–17 (KJV) The cup of blessing which we bless, is it not the communion of the blood of Christ? The bread which we break, is it not the communion of the body of Christ? For we being many are one bread, and one body: for we are all partakers of that one bread.
Does the Supper save? Not by itself. Christ saves, and we receive Him by faith; the Supper nourishes that faith.
John 6:35 (KJV) And Jesus said unto them, I am the bread of life: he that cometh to me shall never hunger; and he that believeth on me shall never thirst.
(Reformed teaching takes John 6 as chiefly about believing; the Supper is the visible Word that strengthens this believing.)
1 Corinthians 11:23–29 (KJV) For I have received of the Lord that which also I delivered unto you, That the Lord Jesus the same night in which he was betrayed took bread: And when he had given thanks, he brake it, and said, Take, eat: this is my body, which is broken for you: this do in remembrance of me. After the same manner also he took the cup, when he had supped, saying, This cup is the new testament in my blood: this do ye, as oft as ye drink it, in remembrance of me. For as often as ye eat this bread, and drink this cup, ye do shew the Lord’s death till he come. Wherefore whosoever shall eat this bread, and drink this cup of the Lord, unworthily, shall be guilty of the body and blood of the Lord. But let a man examine himself, and so let him eat of that bread, and drink of that cup. For he that eateth and drinketh unworthily, eateth and drinketh damnation to himself, not discerning the Lord’s body.
Hypotheticals:
Sofia is anxious: “My faith feels small.” Pastors say, “The Supper is for weak believers who truly trust Christ. Examine yourself, repent, and come.”
Ethan is in open, unrepentant sin. Out of love, elders withhold him from the Table until repentance.
1 Corinthians 5:11–13 (KJV) But now I have written unto you not to keep company, if any man that is called a brother be a fornicator, or covetous… with such an one no not to eat. For what have I to do to judge them also that are without? do not ye judge them that are within? But them that are without God judgeth. Therefore put away from among yourselves that wicked person.
Often, in gathered worship:
Acts 2:42 (KJV) And they continued stedfastly in the apostles’ doctrine and fellowship, and in breaking of bread, and in prayers.
Acts 20:7 (KJV) And upon the first day of the week, when the disciples came together to break bread, Paul preached unto them…
“As often” leaves frequency to pastoral wisdom; many Reformed churches practice weekly or regular communion to nourish faith (1 Cor. 11:26).
Practical execution (Westminster-shaped):
Hypotheticals:
The most biblically correct way to understand and execute them, in this classic Reformed frame, is: