I.--THE CHRIST (xvi. 13-20).
The faith test is a strictly personal one. We have seen how the Master has, so to speak, focussed His gospel in Himself. He had begun by preaching the Gospel of the Kingdom, and calling men to repentance; but as time passed on He found it necessary to make a more personal appeal, pressing His invitations in the winning form, "Come unto Me." When things came to a crisis in Galilee, He first in symbol and then in word set Himself before the people as the bread of life, which each one must receive and eat if he would live. Thus He has been making it more and more evident that the only way to receive the kingdom of God is to welcome Himself as the Son of the living God come to claim the hearts of men for His Father in heaven. How is it with the little band? Is theirs the popular notion, which classes the Son of God as only one among other gifted sons of men, or do they welcome Him in the plenitude of His divine prerogative and power? Hence the first inquiry, which brings out the answer: "Some say that Thou art John the Baptist; some, Elias; and others, Jeremias, or one of the prophets." This is manifestly the popular idea at its highest and best. There were, no doubt, among the people those whose thought already was "Away with Him! away with Him!" But it might well go without saying that the disciples had no sympathy with these. It did, however, remain to be seen whether they were not content, like the best of the people, to accept Him as a teacher sent from God, a great prophet of Israel, or at most a John the Baptist, the mere herald of the coming King. We can imagine, then, with what intensity of feeling the Master would look into the disciples' eyes as He put the testing question, "But whom say _ye_ that I am?" and with what joy He would hail the ready response of their spokesman Peter, when, with eyes full of heavenly light and heart glowing with sacred fire, he exclaimed, "Thou art the Christ, the Son of the living God!"
It would be beyond belief, were it not so sadly familiar a fact, that some, professing honestly to interpret this passage, resolve the answer of the apostle into little or nothing more than the popular idea, as if the Sonship here referred to were only what any prophet or righteous man might claim. He surely must be wilfully blind who does not see that the apostolic answer which the Lord accepts is wide as the poles from the popular notions He so decisively rejects; and this is made peculiarly emphatic by the striking words with which the true answer is welcomed--the Saviour's first personal beatitude (as if to suggest, His is the kingdom of heaven--cf. Matt. v. 3, 10): "Blessed art thou, Simon Bar-jona: for flesh and blood hath not revealed it unto thee, but My Father which is in heaven." It will be remembered that, in asserting His own personal relation to the Father, Christ had said: "No man knoweth the Son, but the Father; neither knoweth any man the Father, save the Son, and he to whomsoever the Son will reveal Him" (xi. 27); and now that to one at least the Father has been revealed in the Son, He recognises the fact with joy. These notions of the people about Him were but earth-born notions, the surmisings of "flesh and blood": this faith of the true apostle was born from above; it could have come only from heaven.
Now at last, therefore, the foundation is laid, and the building of the spiritual temple is begun. The words which follow (ver. 18) are quite natural and free from most, if not from all, the difficulties in which perverse human ingenuity has entangled them, if only we bear in mind the circumstances and surroundings. The little group is standing on one of the huge rocky flanks of mighty Hermon, great boulders here and there around them; and in all probability, well in sight, some great stones cut out of the rock and made ready for use in building, like those still to be seen in the neighbourhood of Baalbec, to the north of Hermon; for this region was famous for its great temples. Now, when we remember that the two words our Lord uses (πέτρος and πέτρα) for "rock" in our version have not precisely the same meaning--the one (Petros, Peter) signifying a piece of rock, a stone, the other (Petra) suggesting rather the great bed-rock out of which these stones are cut and on which they are lying--we can understand that, while the reference is certainly in the first place to Peter himself, the main thing is the great fact just brought out that he is resting, in the strength of faith, on God as revealed in His Son. Thus, while Peter is certainly the piece of rock, the first stone which is laid upon the great underlying foundation on which all the faithful build, and therefore is in a sense--the common popular sense, in fact--the foundation stone, yet the foundation of all is the Bed-Rock, on which the first stone and all other stones are laid. Bearing this well in mind, we further see that there is no inconsistency between this and those other scriptures in which God is represented as alone the Rock of our salvation. The Bed-Rock, "the Rock of Ages," is here, as elsewhere, God as revealed in His Son, and Peter is the first stone "well and truly laid" upon it.