If we have read the entire chapter sixteen, we can hardly imagine that King Asa is the same man who prayed the prayer that is our Bible verse of today. King Asa had lost his deep dependence on God. He had become so successful, that he forgot Who had granted him this success.
By the way, this is not that strange. How many people used to know that utter dependence on the Lord long ago, at the start of their life career? People who - in times of prosperity - forgot Him Who had given them that prosperity. There is nothing new under the sun, but it is still shocking.
Had God not - twenty-six years before - given Asa an incredible victory in answer to his prayer? The Cushites, an invincible army of enemies, had been defeated (2 Chronicles 14). But now Asa was of a different opinion. His success had made him self-confident: not God would save him and his people, no, his political sense would provide a solution, and the good result was to be celebrated.
But at the same time there was a man in Israel who still reckoned with God and who was not deceived by the hubris of king Asa who had become too busy to remember the great deeds of God. The seer Hanani knew that the victory would have been much greater if the king would have trusted in God.
But as long as complacent people are more pleased with the reasonable results of their own wisdom, they will choose those, instead of the divine deliverance that will be revealed when their heart is truly committed to Him.