I think what he means is he has come to bring the kingdom of God to the earth and how he wishes the kingdom of God were already established everywhere on earth. I have come to bring fire to the earth and how I wish it were blazing already . The fire Jesus came to bring is the fire of love, the fire of hope. Bringing fire to the earth, doing anything good, is going to run into the opposition of evil. Jesus said, There is a baptism I must still receive, and how great is my distress till it is over.
Baptism means going completely under the water.
Jesus described the opposition he received as a baptism which would ultimately end in his death. There is a baptism I must still receive, and how great is my distress till it is over. Let us not be so foolish to think that the devil does not exist. Every attempt at good is attacked in one way or another. Notice also in our Gospel that attempts to do good will automatically cause division.