Heidelberg Catechism 38.105

Chapter 38 — Lord's Day 38

Section 105. Q. 105: What is God's will for you in the sixth commandment? A. I am not to belittle, insult, hate, or kill my neighbor — not by my thoughts, my words, my look or gesture, and certainly not by actual deeds — and I am not to be party to this in others; rather, I am to put away all desire for revenge. I am not to harm or recklessly endanger myself either. Prevention of murder is also why government is armed with the sword.