How do we know the commandment 'thou shalt not kill' is true?

The truth of the commandment 'thou shalt not kill' is firmly rooted in scripture, both in the Old and New Testaments. It is not only the directive against murder that we see, but it also reflects God's character and His view of humanity. By creating humans in His image, God has instituted a value upon life that is beyond mere legality. The call to respect life and refrain from murder can be found throughout the Bible, including the teachings of Jesus in Matthew 5, where He expounds on the heart's intentions behind the act, marking the commandment as more than a principle, but a fundamental aspect of living in accordance with God’s will.