The Holy Trinity

(Extracts from Francis Turretin, edited into modern English)

1. Why the Doctrine of the Trinity Matters

Francis Turretin taught that the doctrine of the Trinity is not a side issue. It stands at the heart of the Christian faith. If we misunderstand who God is, we will misunderstand salvation, worship, prayer, and the gospel itself.

The Trinity is not a human invention. It is not based on philosophy or speculation. It is a truth revealed by God in Scripture and must be received by faith, carefully explained, and defended against error.

2. What We Mean by the Trinity

Turretin summarizes the doctrine this way:

There is one true God in essence, and three distinct persons in that one essence: the Father, the Son, and the Holy Spirit.

This statement guards three biblical truths at the same time:

1. God is one (against polytheism)

2. The Father, Son, and Spirit are distinct persons (against modalism)

3. Each person is truly God (against Arianism and similar errors)

If any one of these is denied, the doctrine collapses.

3. One Divine Essence

Turretin insists that God is one in being or essence.

• There is only one divine nature

• This nature is simple, eternal, infinite, and indivisible

• The Father, Son, and Holy Spirit do not each have a separate essence

• They all fully possess the same undivided divine essence

This means:

• The Son is not “part” of God

• The Spirit is not a lesser deity

• God is not divided into three pieces

God is numerically one, not merely one in agreement or purpose.

4. Three Real and Distinct Persons

While God is one in essence, He exists as three persons.

Turretin defines a divine person as:

A subsistence in the divine essence, distinguished by an incommunicable personal property.

In simple terms:

• A person is not a separate being

• A person is someone, not something

• Each person is truly personal and relational

The persons are:

• Not three gods

• Not three modes

• Not three names for the same person

They are really distinct, yet never divided.

5. How the Persons Are Distinguished

Turretin is careful here. The persons are not distinguished by essence, power, or will, since these are shared fully by all three. They are distinguished by their personal relations of origin.

The Father

• Is unbegotten

• He is from no one

• He is the source or fountain of the Trinity

The Son

• Is eternally begotten of the Father

• Not created

• Not born in time

• His generation is eternal, spiritual, and incomprehensible

The Holy Spirit

• Eternally proceeds from the Father and the Son

• Not made

• Not begotten

• His procession is eternal, not temporal

These relations:

• Do not divide God

• Do not imply inferiority

• Do not involve time or change

They describe who God eternally is, not what He became.

6. Equality of the Persons

Turretin strongly affirms that the Father, Son, and Spirit are equal in essence, glory, power, and majesty.

• The Son is not less than the Father

• The Spirit is not subordinate in nature

• Any order among the persons is relational, not essential

This protects the full deity of Christ and the Spirit.

If Christ is not fully God:

• He cannot truly save

• His sacrifice has no infinite value

If the Spirit is not fully God:

• He cannot give new life

• He cannot dwell in believers as God

7. Unity of Will and Action

Another key point in Turretin’s teaching:

The Trinity works inseparably in all divine actions.

This means:

• The Father, Son, and Spirit do not act independently

• Every external work of God is the work of the one God

Yet Scripture often shows a personal order:

• The Father plans

• The Son accomplishes

• The Spirit applies

This does not divide God’s work. It shows harmony, not separation.

8. The Trinity Revealed in Scripture

Turretin stresses that the Trinity is known only by divine revelation, not by human reason alone.

Scripture reveals:

• The oneness of God

• The deity of the Father, Son, and Spirit

• The personal distinctions between them

The doctrine is not based on one verse, but on the whole testimony of Scripture rightly understood.

9. Common Errors Turretin Refutes

Turretin carefully rejects several false views:

Modalism

• Says God is one person who appears in three roles

• Destroys real personal distinctions

Arianism

• Says the Son is created and not fully God

• Undermines salvation and worship

Tritheism

• Says there are three separate gods

• Denies the unity of God

The orthodox doctrine avoids all these by holding unity of essence and distinction of persons together.

10. Practical Use of the Doctrine

Turretin never treats the Trinity as mere theory.

For Worship

• We worship one God

• Through the Son

• By the Spirit

For Prayer

• We pray to the Father

• In the name of the Son

• With the help of the Spirit

For Salvation

• The Father elects

• The Son redeems

• The Spirit regenerates and sanctifies

Remove the Trinity, and the gospel collapses.

11. Humility and Reverence

Turretin ends with reverence. The Trinity is:

• Truly revealed

• Clearly taught

• Yet beyond full human comprehension

We must speak carefully, think biblically, and worship humbly.

We do not explain God to master Him.
We confess God to adore Him.

Summary in One Sentence

The Holy Trinity is one God in three distinct persons, equal in essence and glory, distinguished by eternal relations, revealed in Scripture, and essential to true faith, worship, and salvation.