Why Do Christians Believe in the Trinity?

A Reasonable Answer to Unitarian Criticism of Trinitarian Doctrine

Trinity Defined
Muslims and Unitarians criticize the idea of the Trinity as illogical; they say it violates the logical Law of Non-contradiction: "A" cannot be "non-A" at the same time and in the same respect (or aspect). They claim that Christians say that three gods, the Father, the Son, and the Spirit are one God. And if that were what the doctrine said, they would be correct in rejecting it as illogical.

Muslims misunderstand the doctrine, perhaps, because many Christians misunderstand it and are unable to correctly state it. Following Dr. Walter Martin, the doctrine can be stated thus: The one God eternally exists as the Father, the Son, and the Spirit. Thus, God is one as to his being, essence or nature, but three as to Persons.

Oneness in Diversity
Now in the Old Testament, God’s oneness is expressed in the word echod, which is a unity that contains diversity. For example, this word occurs in the Jewish affirmation of faith of Deuteronomy 6:4, the Shema: “Hear, O Israel, the LORD our God, is one LORD.” Echod also occurs in Genesis 2:24: “For this reason a man will leave his father and mother and be united to his wife, and they will become one flesh.”

We often say that marriage is an image of the relationship of God and man, which is based on the biblical metaphor of Christ as the Bridegroom and the collective Body of Christ, the Church, as his Bride. (The individual believer, male or female, is not a “bride” of Christ, and “bridal mysticism” along this line has led to false doctrine and demonization.) But the profoundest symbolism of marriage is in its imaging of the loving unity of the Persons of the Holy Trinity.

Threeness
The threeness of God makes the Apostle John's statement in 1 John 4:8 and again in verse 16 that “God is love” possible. The three persons have been bound together in the unity of perfect love forever. God's love is the structural glue that unites the Trinity and forms the basis for God's fatherly love and of Christ’s husbandly love for the church. Love as I—Thou relationship is only possible among two or more persons. Thus for God to be love, the One God must have more than one Person within his unitary Being.

Consequences of Unitarianism
Muslims deny that God is Trinity and affirm that He is unitary. Logically enough, then, they deny that God deigns to call himself the Father of any human being. Their God is a monad, our Judge, exalted, utterly transcendent. And that explains why he is not seen as a loving father. Love as I—Thou relationship is not possible within a monistic God and therefore a fatherly relationship with his creatures is not to be expected. This is the logical result of any form of unitarianism and should be pointed out to Unitarian-Universalists and to Jews, who lack the logical rigor of Muslims in this respect.

C. S. Lewis on Relational Groups?

Fern-seed and Elephants and Other Essays on Christianity

By C. S. Lewis, Ed Walter Hooper, © 1975 Fontana/Collins

I made some notes a while back on this little known book of Lewis's essays. They seem to relate to what we are trying to be in our focus groups at Trinity Alliance--David


Christianity is not solitary and individualistic, but neither is it collective in the world’s sense. The enemy tries to convince us that religion is a private matter and if, to defend it, we import the world’s collectivism into Christianity, we fall into his other stratagem.

The true hierarchy is 1) membership in the Body of Christ, 2) personal and private life, and 3) collective life of the secular community. (12-13). “The secular community, since it exists for our natural good and not for our supernatural, has no higher end than to facilitate and safeguard the family, and friendship, and solitude” (13).


“The Christian is called, not to individualism but to membership in the mystical body” (15). The differences between the secular collective and the mystical body show how Christianity can oppose collectivism without individualism. But the term “member” must be clarified to show how like a family the unity of membership is a unity of unlikes, not likes (16). The church “is not a collective but a Body” (17). “We are summoned from the outset to combine as creatures with our Creator, as mortals with immortal, as redeemed sinners with sinless Redeemer. His presence, the interaction between him and us, must always be the overwhelmingly dominant factor in the life we are to lead within the Body; and any conception of Christian fellowship which does not mean primarily fellowship with him is out of court.” (17)


“Unity is the road to personality” (18).