Training is essential to become a follower. Jesus required discipline to become a disciple. He first chose fishers to be followers. They were the Called (https://www.biblegateway.com/passage/?search=Romans%201&version=GNV) and became followers of which he had Chosen Afterwards he said that any man could follow him. We are The Fishers now in training to become Fishers of Men (Fishermen). “How We Got the Bible: Ancient Manuscripts to the King James Version”:
Why? Romans 1
18 For the wrath of God is revealed from heaven against all ungodliness and unrighteousness of men, who hold the truth in unrighteousness;
19 Because that which may be known of God is manifest in them; for God hath shewed it unto them.
20 For the invisible things of him from the creation of the world are clearly seen, being understood by the things that are made, even his eternal power and Godhead; so that they are without excuse:
21 Because that, when they knew God, they glorified him not as God, neither were thankful; but became vain in their imaginations, and their foolish heart was darkened.
Then said Jesus unto his disciples, If any man will come after me, let him deny himself, and take up his cross, and follow me.
And when he had called the people unto himwith his disciples also, he said unto them, Whosoever will come after me, let him denyhimself, and take up his cross, and follow me.
And he said to them all, If any man will come after me, let him deny himself, and take up his cross daily, and follow me.