"Jesus called out to them, 'Come, follow me, and I will show you how to fish for people!" Matthew 4:19
Jesus didn't say, "Clean up your life first, and then you can come." He simply said, "Come."
Peter, James, and John were grime-under-their-fingernails, stinky-fish-smelling dirty. And Jesus couldn't have been more excited to have them join his band of disciples. Jesus saw in them a willingness to follow and a desire and an ability to be more. They knew their only chance of becoming like him was to follow him.
If we are to truly become like Jesus, there is only one way to do it: Stop what you're doing, drop everything, and follow him. Therefore, it is important that we define what it means to be a folllower of Jesus. Following Jesus is about living like Jesus, loving like Jesus, and leaving what Jesus left behind (which is more people who live like him and love like him).
We hear, we understand, we follow, or maybe it more like: we hear, we follow, and then we understand. We reconsider our old ways in light of his invitation to follow. We repent, turning toward him and his way. We unlearn the habits, thoughts, and desires we once had and begin to form new habits, new thoughts, new desires, and new relationships that lead us down the path that follows Jesus.