John 20:24-31; John 21:1-25

Jesus has appeared back to His disciples after the resurrection and He's giving them instructions. He's giving them the power of the Holy Spirit to glorify God, not further their own agenda. They do not have the power to forgive sins; only Jesus has that power.
Sidebar:
1 John 3:1-3
This is the scripture that describes how we'll be like Christ after the resurrection:
1 Behold, what manner of love the Father hath bestowed upon us, that we should be called the sons of God: therefore the world knoweth us not, because it knew him not.
2 Beloved, now are we the sons of God, and it doth not yet appear what we shall be: but we know that, when he shall appear, we shall be like him; for we shall see him as he is.
3 And every man that hath this hope in him purifieth himself, even as he is pure.

24 But Thomas, one of the twelve, called Didymus (twin), was not with them when Jesus came.
25 The other disciples therefore said unto him, We have seen the Lord. But he said unto them, Except I shall see in his hands the print of the nails, and put my finger into the print of the nails, and thrust my hand into his side, I will not believe. You guys can tell me all you want to, but I won't believe Jesus is back until I see and touch those wounds myself. This verse is where the term Doubting Thomas comes from.
26 And after eight days again his disciples were within, and Thomas with them: then came Jesus, the doors being shut, and stood in the midst, and said, Peace be unto you. Jesus went through the doors; they were shut, He didn't open them; He just went through the doors. It shook them up.
27 Then saith he to Thomas, Reach hither thy finger, and behold my....