2:217
They ask you about the month [the] sacred - (concerning) fighting in it. Say, "Fighting therein (is) a great (sin); but hindering (people) from (the) way (of) Allah, and disbelief in Him and (preventing access to) Al- Al-Haraam, and driving out its people from it, (is) greater (sin) near Allah. And [the] oppression (is) greater than [the] killing." And not they will cease (to) fight with you until they turn you away from your religion, if they are able. And whoever turns away among you from his religion, then dies while he (is) a disbeliever for those became worthless their deeds in the world and the Hereafter. And those (are) companions (of) the Fire, they in it (will) abide forever.
11:118
And if (had) willed your Lord surely He (could) have made the mankind community one, but not they will cease to differ.