Mark 1

Jesus walked along the Sea of Galilee and chose four fisherman to be his followers. Why did they immediately follow Jesus?
Some say they already knew him. Perhaps this was prearranged. Some say that his special presence attracted them and this was a spur of the moment decision. "They left their nets."
Perhaps the Holy Spirit spoke to them and they obeyed his call.
There are some who claimed that these men were related to Jesus, perhaps by marriage. They already knew him well as a relative. Even the parents may have approved of this arrangement.
When we first read this perhaps as kids we took away that this was a miraculous event. Jesus calls these four strangers who are involved in an unclean profession and they immediately obey unquestioningly. Why? There is perhaps a sense of the Force like in Star Wars.
But a more mature relationship with God shows us God never coerces. He always speaks in his still small voice and often gives us reasons for his will for our lives.
Uusually he prepares us for the things he wants us to do. Yes, he asks us to step out in faith. No amount of preparation that God did in these men's lives would eliminate the step of faith.
They were leaving their families and their livelihoods behind. They knew the sea. Now they would travel on the land. They would be doing new things.
Jesus did what any great leader will do. He chose, prepared, and trained his successors.