Matthew 28:17
YLT - 17 And having seen him, they bowed to him, but some did waver.
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Of the apostles we know that Thomas was one who doubted until he actually saw and touched Jesus. The disciples, of which there were about 120, did see Jesus, but there is no record that they touched or handled his body. The ones who doubted may have thought they were only seeing a ghost or apparition.