This is the very question which Jesus still puts to the conscience of every man, and on the answer given to it does the salvation of every man still depend. How often also is the answer which our hearts would return, the very same with that which was made by the blind man to Christ: "Who is He, Lord, that I might believe on Him?"
I. First, let us see what the question means. It is plain that it means more than a mere nominal belief, like that of a person who had learnt his creed by heart, and had been told in his childhood who Christ was, without having in after life thought about Him at all, and yet without having his old belief overthrown, so that, if he should be put in mind, he would still possess it. Such a belief on the Son of God is no belief at all. We know that the belief spoken of in the text is a true and lively assurance that Christ is indeed the Son of God, from whom we shall receive our eternal sentence of happiness or misery, according as we please Him or no; and any man who does hold such an assurance strongly cannot easily avoid being influenced by it in his conduct.
II. There are many who, in a very strict sense, may be said not to know who the Son of God is: (1) Those who consider Him as a great prophet, but are never led to regard Him with that faith and love and adoration which His character, as revealed in the Scriptures, demands. (2) A second class of persons, who do not know the Son of God, consists of those to whom the expression of the Apostle, that we walk by faith and not by sight, appears, if they would confess the truth, utterly wild and unreasonable. Many of these men attend church, express their belief in the Gospel, and not unfrequently lament and condemn the progress of infidelity. This they do not out of pretence, but thinking themselves very sincere; they have a respect for Christianity, and they propose to themselves, when they think of such things, to profit from its rewards hereafter. But if those labourers in the parable, who were called early in the morning, had passed the day in idleness, resolving to begin their work at the eleventh hour, they would in vain have asked for the wages of their labour. If we live by sight, we must not expect to die by faith.
T. Arnold, Sermons,vol. i., p. 146.
References: John 9:35; John 9:36. Spurgeon, Sermons,vol. xviii., No. 1088. John 9:35-38. H. W. Beecher, Sermons,3rd series, p. 623, Ibid., Christian World Pulpit,vol. iv., p. 58; J. R. Harington, Ibid.,vol. vii., p. 211; Bishop Harvey Goodwin, Oxford University Herald,June 20th, 1885; W. Hay Aitken, Mission Sermons,vol. i., p. 51. Joh 9:38. W. F. Hook, Sermons on the Miracles,vol. ii., p. 119. John 9:39. Spurgeon, Sermons,vol. xxx., No. 1798; Clergyman's Magazine,vol. iii., p. 27. Homiletic Magazine,vol. xiii., p. 261; vol. xix., p. 303; F. D. Maurice, The Gospel of St. John,p. 259. John 9:41. S. Baring Gould, One Hundred Sermon Sketches,p. 8. John 9 G. Macdonald, The Miracles of Our Lord,p. 61. Joh 10:1-10. Clergyman's Magazine,vol. ii., p. 273.