THAT there is unity in the Godhead no Christian denies; while he fully believes three Persons in the Godhead, even the Father, and the Son, and the Holy Spirit (Matt. 28:19).
Nor is this truth to be enfeebled in the least degree. He who allows no more in the Godhead than three aspects of one Person is not a Christian, but a deceiver and an antichrist. He does not confess the fully revealed and true God, not the Godhead merely in three characters but in Three Persons; and so distinct that the Father could send the Son (1 John 4:14), and the Holy Ghost descend on that Son in the presence of the Father and in the consciousness of the Son (Mark 1:10, 11), as it was even outwardly before man also (John 1:33, 34).
The Trinity
Such is the early and immense fact recorded in the Gospels, a clear witness to “the Trinity." What sympathy can one have with those who, overlooking such a fact, stumble over the term? Why be so servile to the letter, and so anxious to get rid of a word because it is not in the Bible? The thing is distinctly there; the truth, not only open in the New Testament, but pervading the Bible (in a more veiled form, characteristic of the Old Testament in general) from the first chapter to the last.
One cannot now read the first chapter of Genesis intelligently without seeing that there are more Persons than One in the Godhead. Even the first verse of the first chapter yields a positive though gradual preparation for divulging it, at least after it was revealed.
The Plural Noun and the Singular Verb
Do you ask how this can be? “In the beginning God created” (Gen. 1:1). Perhaps all may not have heard but it is nevertheless true, that in the original Hebrew “God" is in the plural, naturally pointing to more than one Person; yet "created" is in the singular, a form not used where it speaks of heathen gods, but where it speaks of the living God. With the gods of the nations, the verb is plural. With the true God, although the subject be in the plural, the verb is often in the singular. Cases like Gen. 20:13 ("God caused") where the verb is plural (like the noun), prove that God (Elohim) was known to be a true plural.
One God, Three Persons
Could anything prepare better for revealing unity of the nature and plurality of the Persons? Granted that none in the Old Testament could certainly see the Three Persons as revealed later; even the believer had to wait until the New Testament for full light and truth. But when it came in Christ and by the Spirit, the peculiar (grammatical) concord where God's name occurs of old could not but strike those who heed every word of Holy Writ.
Every Word Inspired
Men who hold lax views of inspiration may no doubt dispute the force of any word because their views are unbelieving and pernicious; for these necessarily enfeeble and undermine inspiration as God has revealed it, and as His Spirit reasons on it. No error has consequences more widely spread than limiting inspiration to God's thoughts in general, and denying it to His written words.
The Day of Atonement, by W. Kelly, pp. 50-52