I Samuel 26-27

"And the Lord will repay each man for his righteousness and faithfulness" (26:23). David spared King Saul's life a second time, choosing to do what he believed was right, rather than what was strategic. David believed that God would eventually deal with Saul, but to attempt to be the agent of God's vengeance was wrong. Killing Saul might have put David on the throne sooner, yet it would also have crossed a moral line with spiritual consequences.

If God is real, then choosing to please Him is more important than any other agenda - however urgent or "necessary."