Why the Doctrine of the Trinity Is Fundamental to Salvation

“…which faith, except everyone do keep whole and undefiled,
without doubt he shall perish everlastingly.”
—Athanasian Creed

On the basis of the clear doctrine of Holy Scripture, all true Lutherans affirm with the Apology of the Augsburg Confession:

We declare that we believe and teach that there is one divine essence, undivided, and yet, that there are three distinct persons, of the same divine essence and co-eternal, Father, Son and Holy Ghost.  This article we have always taught and defended, and we believe that it has, in Holy Scripture, sure and firm testimonies that cannot be overthrown.  And we constantly affirm that those thinking otherwise are outside the Church of Christ and are idolaters and insult God. (Apology, I, Triglot, p. 103).

As Dr. Luther put it: “Of these Persons each one is whole God, besides whom there is no other God.”

In his Doctrinal Theology, John Gerhard states: “God always from the beginning revealed Himself as three distinct Persons in one essence” (p.157).  And in Christian Dogmatics, Dr. J. T. Mueller lists the Old Testament proofs numbering eight different types ( p.159f), adding this declaration on p. 160, in which we have written out the cited passages for the reader’s convenience:

Certainly no one has ever been saved who did not believe in the True God (the Triune God) and the true Savior of the world (the Second Person of the Godhead), since this truth is stated so clearly in Scripture: “Neither is there salvation in any other: for there is none other name under heaven given among men, whereby we must be saved” (Acts 4:12),  “That all men should honor the Son, even as they honor the Father. He that honoreth not the Son honoreth not the Father, which hath sent Him” John 5:23;  “Whosoever denieth the Son, the same hath not the Father: [but] he that acknowledgeth the Son hath the Father also” I John 2:23.

Our Lord Jesus Christ, in His High‑Priestly prayer, says to His Father: “…Father, the hour is come; glorify Thy Son, that Thy Son also may glorify Thee: As Thou hast given Him power over all flesh, that He should give eternal life to as many as Thou hast given Him. And this is life eternal, that they might know Thee, the only true God, and Jesus Christ, whom Thou hast sent. I have glorified Thee on the earth: I have finished the work which Thou gavest me to do. And now, O Father, glorify Thou me with Thine own self with the glory which I had with Thee before the world was” (John 17:1b‑5).

Clearly, to have eternal life, one must be given the true knowledge of the Only True God; and this knowledge comes only through Jesus Christ: “For the law was given by Moses, but grace and truth came by Jesus Christ. No man hath seen God at any time; the only begotten Son, which is in the bosom of the Father, He hath declared Him” (John 1:17‑18).

Holy Scripture teaches that, apart from the Gospel, all men are “without Christ…having no hope and without God in the world” (Ephesians 2:12).  This is why God revealed the Gospel already to Adam and Eve immediately after the fall (Genesis 3:15) and throughout the Old Testament: “To Him give all the prophets witness, that through His name whosoever believeth in Him shall receive remission of sins” (Acts 10:43).

The Bible tells us that all the so‑called “gods” of this world are idols having no existence or power save that of demonic influence:  “What say I then? that the idol is anything, or that which is offered in sacrifice to idols is anything?  But I say, that the things which the Gentiles sacrifice, they sacrifice to devils, and not to God: and I would not that ye should have fellowship with devils. Ye cannot drink the cup of the Lord, and the cup of devils: ye cannot be partakers of the Lord’s table, and of the table of devils” (I Corinthians 10:19‑21; cf. also Jeremiah 2:11; Leviticus 19:4; Isaiah 44:6‑20; Jeremiah 2:26‑28; Psalm 115:1‑9; 135:15‑17; and especially I Corinthians 8:4, 6).

As the Lutheran dogmatician Koenig states: “The necessity of believing this doctrine is such that it not only cannot be denied, but even cannot be ignored by any one without a loss of salvation.  John 17:3; John 5:11,12; I John 2:23; John 5:23; II Thessalonians 1:8.”  More detailed, John Gerhard (III, 209):

It is necessary for all who are to be saved to know and believe the mystery of the Trinity: (a) we exclude from men who are to be saved, not only those who deny, but also those who are ignorant of the Trinity… (b) we do not require of all members of the Church an equal degree of knowledge, since the light of spiritual knowledge and faith is brighter in some and more obscure in others;  (c) nor do we require of those who are to be saved a perfect and full comprehension and an intuitive knowledge of this mystery, since we cannot attain this in this life… but we assert only this, that for the catholic [universal, Christian] faith, necessary to all who are to be saved, not a confused and implied, but a distinct and explicit knowledge of the three persons of the Godhead is required.

The reason (III, 210): “Whoever is ignorant of the mystery of the Trinity does not acknowledge God as He has revealed Himself in His Word, and is ignorant of the definition of God given in the Scriptures.  The mystery of the Trinity being ignored or denied, the entire economy of salvation is ignored or denied.”

In our present evil age of “political correctness,” the Bible doctrine of exclusive salvation in Christ Jesus, the second person of the Holy Trinity, true God manifest in the flesh, is vilified by many as “hate‑speech.”  How long before the state actually moves against those who “earnestly contend for the faith which was once delivered unto the saints” (Jude 3) is anyone’s guess.  At our Baptism we vowed that, by God’s grace and power, we would suffer all, even death, rather than deny the only true God, the Holy Trinity, whom we worship exclusively, in whose Name we are regenerated and made heirs of heaven.  God will strengthen us through His saving Word to enable us to remain steadfast in the true faith unto our end.  God’s faithfulness is the guarantee of our faithfulness:  “Faithful is He that calleth you, who also will do it” (I Thessalonians 5:24).  “The Lord is faithful, who shall stablish you and keep you from evil” (II Thessalonians 3:3).  “Ye are kept by the power of God through faith unto salvation” (I Peter 1:5).

Beloved, God will enable us to keep the faith whole and undefiled, so that we do not perish everlastingly but have eternal life.  Our only Savior assures us:

“Let not your heart be troubled: ye believe in God, believe also in Me.  In My Father’s house are many mansions: if it were not so, I would have told you. I go to prepare a place for you. And if I go and prepare a place for you, I will come again, and receive you unto Myself; that where I am, there ye may be also. And whither I go ye know, and the way ye know.”  Thomas saith unto him, “Lord, we know not whither Thou goest; and how can we know the way?” Jesus saith unto him, “I am the way, the truth, and the life: no man cometh unto the Father, but by Me.  If ye had known Me, ye should have known My Father also: and from henceforth ye know Him, and have seen Him” (John 14:1‑7).

God grant us so to believe, for Jesus’ sake.  Amen!

—E. J. W.