How To Treat Strangers | Answering the Atheist

Inquiry:
How should strangers be treated? Should they be killed (Numbers 1:41; 3:10, 38; 18:7; Deuteronomy 7:2) or should they be treated kindly (Exodus 22:21; Leviticus 19:33-34; Deuteronomy 10:19; Jeremiah 22:3; Zechariah 7:10; Matthew 25:35)? Is there a contradiction?