Blessed Are Those Who Have Not Seen and yet Have Believed

This Sunday our Pastor will be preaching. We read in chapter 20 of John’s account of the resurrection of Jesus. Thomas, one of the disciples of Jesus says he will not believe that Jesus has risen from the dead unless he can actually see the wounds made by the nails and the spear.
Jesus comes to Thomas and gives him that opportunity. Jesus says to him that those who have not seen and believe are blessed.
Is seeing believing? Can we believe without seeing?