Psalm 3:7

Arise, O Lord; save me, O my God! For You have struck all my enemies on the cheek; You have broken the teeth of the wicked.
Psalm 3:7, Modern English Version (MEV)
 
At the risk of sounding irreverent, these words have the ring of God's people standing on the sidelines as they cheer God on as He fights His opponent in a boxing ring. This is not meant to indicate in any way that what God's people are doing is wrong. In fact, Scripture teaches us over and over, particularly through the history of Israel, that God does fight our battles for us. One of the main reasons we see so many failures in those battles is because we try to help God and simply end up getting in His way. Step aside, Christians, and let God do what He does best.
 
Albert Barnes, in his Notes on the Bible, explains it this way:
 
Arise, O Lord - This is a common mode of calling upon God in the Scriptures, as if he had been sitting still, or had been inactive. It is, of course, language taken from human conceptions, for in the intervals of active effort, in labor or in battle, we sit or lie down, and when we engage in toil we arise from our sitting or recumbent posture. So the mind accustoms itself to think of God. The idea is simply that David now calls upon God to interpose in his behalf and to deliver him.
 
Save me, O my God - He was still surrounded by numerous enemies, and he, therefore, calls earnestly upon God to help him. In accordance with a common usage in the Scriptures, and with what is right for all the people of God, he calls him “his” God: “O my God.” That is, he was the God whom he recognized as his God in distinction from all idols, and who had manifested himself as his God by the many mercies which he had conferred on him.
 
For thou hast smitten all mine enemies - That is, in former exigencies, or on former occasions. In his conflicts with Saul, with the Philistines, and with the surrounding nations, he had done this; and as the result of all he had established him on the throne, and placed him over the realm. In the remembrance of all this he appeals with the full confidence that what God had done for him before He would do now, and that, notwithstanding he was surrounded with numerous foes, He would again interpose. So we may derive comfort and assurance in present trouble or danger from the recollection of what God has done for us in former times. He who has saved us in former perils can still save us; we may believe that he who did not forsake us in those perils will not leave us now.
 
Upon the cheek-bone - This language seems to be taken from a comparison of his enemies with wild beasts; and the idea is, that God had disarmed them as one would a lion or tiger by breaking out his teeth. The cheek-bone denotes the bone in which the teeth are placed; and to smite that, is to disarm the animal. The idea here is not that of “insult,” therefore; but the meaning is simply that he had deprived them of the power of doing him wrong.
 
Thou hast broken the teeth of the ungodly - The same idea is here expressed under another form, “as if” the teeth of wild animals were broken out, rendering them harmless. As God had thus disarmed his enemies in times past, the psalmist hoped that he would do the same thing now, and he confidently called on him to do it.