Allah 27

4. When you encounter those who disbelieve, strike at their necks. Then, when you have routed them, bind them firmly. Then, either release them by grace, or by ransom, until war lays down its burdens. Had Allah willed, He could have defeated them Himself, but He thus tests some of you by means of others. As for those who are killed in the way of Allah, He will not let their deeds go to waste.

The Quran
Chapter 47, Muhammad