God is the giver of life. He is the one who gives life, he gets to decide when life should come to an end, not human beings.
God speaks. He revealed his laws and decrees through Moses to the people of Israel long ago.
God is just. Those who take the life of fellow human beings or treat their neighbour as if they do not exist will be judged. God punishes sin.
God is concerned for true and proper worship. He does not want people to submit to formal worship regulations while refusing to live in accordance with his will.
21 “You have heard that it was said to those of old, ‘You shall not murder; and whoever murders will be liable to judgment.’