My immediate response would probably be God’s special revelation in His authoritative and inerrant Word.
The Scriptures give us evidence enough, then, that Christ is God. But the Scriptures are far from giving us all the evidence we have. There is, for example, the revolution which Christ has wrought in the world. If, indeed, it were asked what the most convincing proof of the deity of Christ is, perhaps the best answer would be, just Christianity. The new life He has brought into the world; the new creation which He has produced by His life and work in the world; here are at least His most palpable credentials.
Early in the essay, Warfield clarifies:
A recent writer1 has remarked that our assured conviction of the deity of Christ rests, not upon “proof-texts or passages, nor upon old arguments drawn from these, but upon the general fact of the whole manifestation of Jesus Christ, and of the whole impression left by Him upon the world.” The antithesis is too absolute, and possibly betrays an unwarranted distrust of the evidence of Scripture. To make it just, we should read the statement rather thus: Our conviction of the deity of Christ rests not alone on the scriptural passages which assert it, but also on His entire impression on the world; or perhaps thus: Our conviction rests not more on the scriptural assertions than upon His entire manifestation. Both lines of evidence are valid; and when twisted together form an unbreakable cord. The proof-texts and passages do prove that Jesus was esteemed divine by those who companied with Him; that He esteemed Himself divine; that He was recognized as divine by those who were taught by the Spirit; that, in fine, He was divine. But over and above this Biblical evidence the impression Jesus has left upon the world bears independent testimony to His deity, and it may well be that to many minds this will seem the most conclusive of all its evidences. It certainly is very cogent and impressive.
He closes the article with this:
The supreme proof to every Christian of the deity of his Lord is then his own inner experience of the transforming power of his Lord upon the heart and life. Not more surely does he who feels the present warmth of the sun know that the sun exists, than he who has experienced the re-creative power of the Lord know Him to be his Lord and his God. Here is, perhaps we may say the proper, certainly we must say the most convincing, proof to every Christian of the deity of Christ; a proof which he cannot escape, and to which, whether he is capable of analyzing it or drawing it out in logical statement or not, he cannot fail to yield his sincere and unassailable conviction. Whatever else he may or may not be assured of, he knows that his Redeemer lives. Because He lives, we shall live also—that was the Lord’s own assurance. Because we live, He lives also—that is the ineradicable conviction of every Christian heart.
These quotations come from Benjamin B. Warfield, “The Deity of Christ,” in The Fundamentals: A Testimony to the Truth, ed. R. A. Torrey, A. C. Dixon, et al. (Los Angeles: Bible Institute of Los Angeles, 1917), 2:239–46. [Amazon | Logos]
Warfield is not talking about one being more reliable than the other. Both of these proofs are equally reliable. Rather, he is talking about what has greater power of persuasion—something that can vary from person to person.
The whole thing is worth reading. It gives a glimpse into Warfield’s apologetic method and makes helpful distinctions between proof, argument, persuasion, and warrant.
What do you think? Do you agree with Warfield?