Even though some doubted (vs. 17) He still believed enough in them to direct the disciples to go and reproduce themselves...everywhere. Jesus' last words weren't how much He was gong to miss them, but it was a heart for the lost, hurting people that needed to be loved, embraced and taught how to walk with God.

Matthew 28:16, Matthew 28:17, Matthew 28:18 and Matthew 28:19-20