Charles Ellicott Commentary John 20:29

"Jesus saith unto him, Because thou hast seen me, thou hast believed: blessed [are] they that have not seen, and [yet] have believed." — John 20:29 (ASV)

Jesus says to him, Thomas, because you have seen me, you have believed.—The name “Thomas” is omitted in all the better manuscripts, and the order of the other words suggests that they should be read interrogatively—Jesus says to him, Because you have seen Me, have you believed? The tense of the word rendered “have you believed” is the perfect-present—“have you become, and are you a believer?” The command of John 20:27 had done its work, and the words are words of approval; but they are not entirely so. He had arrived at conviction by means of the senses, but the higher blessedness was that of those who see by the eye of the spirit and not by that of the body; who base their confidence on the conviction of the faith-faculty, and are independent of the changing phenomena of the senses.

Blessed are they that have not seen, and yet have believed.—The truth is expressed in its general form. It is not to be understood in any special sense of the Ten, for the Greek is against it, and the other disciples also had seen and had believed; but it includes all who have become believers without having seen. This blessedness is thought of as existing from the moment of believing, and the act of faith is therefore spoken of in the past tense. The words look forward to the development of the Church which is to be founded upon Apostolic witness, and whose faith must ever be in the unseen. (Compare to Notes on John 1:9 and 1 Peter 1:9.)