We find this verse in the 20th Chapter of John. “Because thou hast seen me – Because you have looked upon my body, and seen the proofs that I am the same Saviour that was crucified.”
When told by the other Apostles that they have seen Jesus, after His crucifixion and resurrection, Thomas said, “Unless I see the nail marks in his hands and put my finger where the nails were, and put my hand into his side, I will not believe.” John 20:25
Days later Jesus returns to the Apostles and says to Thomas, “Put your finger here, see my hands. Reach out your hand and put it into my side. Stop doubting and believe.”
Thomas said to him, “My Lord and my God!” Then Jesus told him, “Because you have seen me, you have believed; blessed are those who have not seen and yet have believed.”
Jesus here approves the faith of Thomas, but more highly commends the faith of those who should believe without having seen.
Blessed – Happy, or worthy of divine approval. The Word signifies that “those who have not seen” would be in some respects more blessed than Thomas. They would manifest higher faith.
That have not seen … Those who should be convinced by the testimony of the Apostles, and by the influences of the Spirit. They would manifest stronger faith. All faith is of things not seen; and God blesses those most who most implicitly rely on his word.
Moreover, the shield of faith described by the apostle Paul in his letter to the Ephesian Christians is of paramount importance because it is the grace “with which you can extinguish all the flaming arrows of the evil one” (Ephesians 6:16). This is not an uncertain promise. Rather, it is divine assurance that faith equips us to escape the very extremities of evil. But what is faith?
First, the Bible defines faith as “being sure of what we hope for and certain of what we do not see” (Hebrews 11:1). Thus, in biblical vernacular, faith is a channel of living trust—an assurance—that stretches from man to God. In other words, it is the object of faith that renders faith faithful.
Furthermore, faith is the assurance that God’s promises will never fail, even if sometimes we do not experience their fulfillment in our mortal existence. Hebrews 11 underscores the fact that we trust God to fulfill his promises for the future (the unseen) based on what he has already fulfilled in the past. Thus, our faith is not blind, but based squarely on God’s proven faithfulness.
Finally, the faith that serves to protect us in spiritual warfare is not to be confused with mere knowledge. Millions worldwide believe in the trustworthiness of Billy Graham. They have heard him proclaim the good news on television and yet do not believe that his message corresponds to reality. Thus, they have the knowledge that it takes to be saved but do not have saving faith. Others hear the message, agree that it corresponds to reality, but due to the hardness of their hearts do not bow. Rather, like the demons, they continue to live in fearful anticipation of the judgment to come (James 2:19). Some, however, have what Scripture describes as genuine justifying faith—a faith that not only knows about the gospel and agrees that its content corresponds to reality, but a faith by which they are transformed.