Matthew 28:19-20

Therefore, go and make disciples of all the nations, baptizing them in the name of the Father and the Son and the Holy Spirit. Teach these new disciples to obey all the commands I have given you. And be sure of this: I am with you always, even to the end of the age.

I wonder if the disciples even understood the weight of this command when Jesus told them during those last moments before He returned to heaven.