Jesus after rose up from the dead showed Himself to His disciple to fortify their faith and clear all doubt.
He needed them to be certain that He was not dead because this would be part of the truth they would share to the world.
After that, Christ commanded them to continue what He was doing, by discipling people for the kingdom.
This responsibility is for every one that believes not just the apostles.
A true disciple will take on the responsibility of sharing the gospel and also to live a life that shows we are God's people.
God never told them to go with nothing in their hands.
He equiped and prepared them through His spirit.
Every believer today carries this same responsibility.
Every Christian has the same purpose and duty.
Being a true disciple does not end with just believing, rather, it also has to do with being obedient, ready to serve and evangelistic because many people needs to know Christ in order to get everlasting life.