Morality for a religious person is closely related to a God, gods, or a higher force beyond him. The concept of Sin that is used by a religious person is also related directly to morality. Sin is disobeying God. Disobeying God is immoral.
Sin is immoral.
Sin produces a sense of guilt. Guilt not Love is the fundamental emotion that religion induces. Obedience to God's rules becomes paramount. Disobeying God's rules is sin, and produces guilt. Similarly God's representative.