The catechism explains that the sixth commandment is not only speaking about physical murder, but also about murderous thoughts in the heart. Pastor Paul van Engelenhoven explains the sin of murder, how the door of Cain’s heart opened, and how the Christian heart’s door is protected from murder.
“Do not be anxious about anything, but in everything by prayer and supplication with thanksgiving let your requests be made known to God.”
Heidelberg Catechism: Lord’s Day 40