What is the fifth commandment of God? The fifth commandment of God is: Thou shalt not kill.
Thou shalt not kill. (Exodus 20:13)
What are we commanded by the fifth commandment? By the fifth commandment we are commanded to take proper care of our own spiritual and bodily well-being and that of our neighbor.
What does the fifth commandment forbid? The fifth commandment forbids murder and suicide, and also fighting, anger, hatred, revenge, drunkenness, reckless driving, and bad example.
Everyone who hates his brother is a murderer. And you know that no murderer has eternal life abiding in him. (I John 3:15)
More on that here -> CCC 2258-2330