I can expect thiss question and im prepared for it
first the verse directly after the "kill disbelievers verse" goes as follows
If one amongst the Pagans ask thee for asylum, grant it to him, so that he may hear the word of Allah; and then escort him to where he can be secure that is because they are men without knowledge. [Al-Quran 9:6]
Also understand this was durring the time when the pagans where attacking the muslims because they where ruining there pagan economic system. its said that at the battle of badr, not only by religious but by historians that the muslims only had 313 men and the enemy had around 1000 better armed men. the muslims where victorious.
Latter we find that when Muhammad (pbuh) entered mecca, he didnt kill anyone yet spared there lives. Even though they once tried to kill him and islam. they did not suceed. Yes islam was a religion that was attacked so its obvious that it will have some verses in the quran concerning war... Also your christian, as ive seen from previous posts, so when david took the holy land, its the same thing.