Here are Bible quotes that refer to killing people for various reasons, including nonbelievers:Death to Followers of Other Religions
Whoever sacrifices to any god, except the Lord alone, shall be doomed. (Exodus 22:19 NAB)

They entered into a covenant to seek the Lord, the God of their fathers, with all their heart and soul; and everyone who would not seek the Lord, the God of Israel, was to be put to death, whether small or great, whether man or woman. 2 Chronicles 15:12-13 NAB
Suppose you hear in one of the towns the LORD your God is giving you that some worthless rabble among you have led their fellow citizens astray by encouraging them to worship foreign gods.  In such cases, you must examine the facts carefully.  If you find it is true and can prove that such a detestable act has occurred among you, you must attack that town and completely destroy all its inhabitants, as well as all the livestock...(2 Chronicles 15:12-13 NAB)

Christianity is not peaceful either.