It can be difficult to avoid revenge. When someone harms us we want to get back. If someone hurts us, we want to hurt them. Being a Christian means rising above this. Jesus tells us to turn the other cheek. Jesus tells us to pray for persecutors. Jesus tells us to love enemies.
But this is not possible completely on our own. It is only possible with God’s grace. God gives us the means to do this. Joseph could have taken revenge on his brothers. But God’s grace enabled him to see a greater plan of God. Since we can in no way be greater than Jesus, let us hear his words.