Abijah had three good years but was suddenly cut off because he didn't remove the idols. One act of faith is only something to build on, not a cause to rest.
The spirit of Babylon is one of self-determination and independence, antagonistic toward every institution of God, even something as basic as God-given gender.
Asa left a few things undone, losing steam in his later years and playing it safe. Idolatry was so ingrained in the land that Asa grew weary in well-doing.