Matthew Bates has a long discussion about the link between continued allegiance and good works. Good works is expressed allegiance.
I think that there should have been more emphasis on the act of giving allegiance. We become a Christian by switching our allegiance from the world to Jesus. We are actually switching from unwitting allegiance to the spiritual powers of evil to allegiance to Jesus.
A switch in allegiance is a pivotal moment with permanent consequences. Once Simon the Zealot switched his allegiance from his zealot group to Jesus, he could not go back. If he had tried, they would have perceived him to be a spy and tried to kill him.
If a soldier in Saul’s army went to live with David in the Cave of Adullum and switched allegiance he could not go back. If he tried to meet with his old friends in Saul’s army, they would kill him because he was a traitor. If he were a senior officer, they would have tried to kill him anyway, because he would know too much.
Switching allegiance is a life and death issue.
When give allegiance to Jesus, we are withdrawing our allegiance to the spiritual powers of evil. They are not happy.