Francis Turretin discusses the difference between the Old and New Covenants with great care, especially in his Institutes of Elenctic Theology. The following is an enhanced rendering in modern English that preserves his theological precision while making it easier to read and teach.

Francis Turretin: The Difference Between the Old and the New Covenant

(Modern English)

The Old and New Covenants are not two different ways of salvation. They have the same author, the same foundation, and the same ultimate purpose: the salvation of sinners through Jesus Christ. The Old Covenant looked forward to Christ who was to come; the New Covenant looks back to Christ who has already come. Both rest upon the grace of God and the promise of redemption through the Mediator.

The difference between them is not that the Old Covenant was a covenant of works while the New Covenant is a covenant of grace. Rather, both belong to the one covenant of grace, though they differ in the manner in which that grace was revealed and administered.

1. The Old Covenant Was More Hidden; the New Covenant Is More Clearly Revealed

The Old Covenant contained the promise of Christ, but Christ was revealed through shadows, types, ceremonies, and symbols. The sacrifices, priesthood, temple, and ceremonies of the law pointed beyond themselves to the coming Messiah.

The New Covenant removes these shadows because Christ Himself has appeared. The reality has replaced the figures; the substance has come where once there were only signs.

As the apostle says:

“These are a shadow of the things to come, but the substance belongs to Christ.”
(Colossians 2:17)

Under the Old Covenant, believers saw Christ from a distance through promises and pictures. Under the New Covenant, believers know Christ as the One who has accomplished redemption.

2. The Old Covenant Had an Earthly Form; the New Covenant Has a More Spiritual and Universal Form

The Old Covenant was administered through the nation of Israel. It included a particular land, a visible kingdom, a physical temple, and national ceremonies.

These things were not the final goal but served as temporary signs pointing toward the greater spiritual realities that would come through Christ.

The New Covenant expands beyond one nation. The blessings of salvation are openly offered to all nations. The people of God are no longer identified by physical descent from Abraham but by faith in Christ.

The promise is fulfilled:

“In you all the families of the earth shall be blessed.”
(Genesis 12:3)

The New Covenant gathers God's people from every tribe, tongue, and nation.

3. The Old Covenant Had a Greater Emphasis on External Commands; the New Covenant Brings Greater Internal Transformation

Turretin explains that the law under the Old Covenant was written primarily on stone tablets and externally presented to the people. The New Covenant brings the same moral law into the heart through the work of the Holy Spirit.

God promised:

“I will put my law within them, and I will write it on their hearts.”
(Jeremiah 31:33)

The difference is not that the Old Covenant lacked grace or that Old Testament believers had no inward work of the Spirit. They were truly regenerated and saved by faith.

Rather, the New Covenant brings a fuller and more abundant communication of the Spirit’s work. What was present in a smaller measure under the Old Covenant is poured out more richly under the New.

4. The Old Covenant Promised Blessings Under Figures; the New Covenant Gives the Fulfillment

The Old Covenant promised forgiveness, fellowship with God, and eternal life, but these blessings were often expressed through earthly pictures:

• Canaan represented the final inheritance.

• The temple represented God's presence.

• Sacrifices represented the true sacrifice of Christ.

• The priesthood represented Christ's eternal priesthood.

The New Covenant reveals that these promises find their true fulfillment in Christ.

The believer now receives:

• Christ as the true Temple,

• Christ as the final Sacrifice,

• Christ as the perfect High Priest,

• Christ as the inheritance of God's people.

The blessings are not merely anticipated; they are accomplished.

5. The Old Covenant Had a Temporary Administration; the New Covenant Has a Permanent Administration

The Old Covenant ceremonies were appointed only until Christ came. Once Christ fulfilled the law's shadows, those ceremonial elements passed away.

Turretin emphasizes that Christ did not destroy the Old Covenant by opposing it; He fulfilled it by bringing it to completion.

The Old Covenant was like the morning light before sunrise. The New Covenant is the full brightness of the day.

The Old Testament saints were saved by looking forward to Christ. New Testament believers are saved by looking back to Christ’s completed work.

The object of faith is the same; only the clarity of revelation differs.

6. The Old Covenant Revealed the Need for a Mediator; the New Covenant Reveals the Mediator Himself

The Old Covenant continually showed humanity’s inability to keep God's law perfectly. The sacrifices had to be repeated because they could never fully remove sin.

But these sacrifices pointed to the perfect sacrifice that would come.

The New Covenant declares:

“By a single offering he has perfected for all time those who are being sanctified.”
(Hebrews 10:14)

Christ is not merely another mediator like Moses. He is the eternal Son of God who has accomplished what all previous mediators could only represent.

Summary of Turretin’s Distinction

Turretin’s Main Point

The Old and New Covenants are not two opposing covenants but two administrations of the one covenant of grace. The Old Covenant was the covenant of grace in its infancy, clothed with shadows and ceremonies. The New Covenant is that same covenant brought into maturity through the coming of Christ.

The difference is not in the way sinners are saved, for salvation has always been by grace through faith in the promised Redeemer. The difference is in the clarity, fullness, freedom, and power with which God's saving grace is revealed.

The fathers under the Old Covenant looked forward to Christ’s coming; believers under the New Covenant rejoice that Christ has come, has died, has risen, and now reigns forever.