How can a sensible person understand that, in order to forgive sin, God leads humanity ever deeper into sin finally even to the point of becoming God's killer, Do Abrahams children receive forgiveness by killing their God? Why then does God demand prayer and obedience? Why then does God set up commandments for humanity?.

Answer: God gave humanity commandments. As humanity, in freedom of will, increasingly defied these commandments, God decided to show His love not only through teaching but also by sacrificing His only son (read Jn 3,16 onwards).