David had opportunities under self defense, to kill King Saul who had needlessly been trying to assassinate him. But David did not seize these opportunities because Saul was the anointed of God. No matter how badly Saul behaved, he had been ordained of God. God honored David’s respect for authority and made him a man of authority. He became King of Judah and Israel and many will argue that He was the leader of the known world at the time. Even Jesus told his persecutors that they had no power over him except it be given to them by God. In other words, the authority they had over Him in that moment was ordained by God.
God calls us to be subject to authority, time and time again. To pray for leadership. He reminds us that he ordained every leader on earth and allows them hold the mantle of authority they currently posess. Leaders are often criticized for bad decisions, but when this criticism degenerates into insults and gross disrespect, then biblical boundaries are being crossed. If a leader is asking you not to follow Christ, then of course you can’t comply with that but if a leader through the legal channels of his authority is asking you to pay a tax or comply with law then by all means, give to Cesar what is Cesar’s and to God what is God. Be subject to authority even if you do not agree with it for believe it or not, that authority was ordained by God.
Let every soul be subject unto the higher powers. For there is no power but of God: the powers that be are ordained of God – Romans 13:1