Sorry to hear he is devoted to an angel, instead of the Savior. The first is idolatry. The second leads to eternal life.
to each his own. and why does God use angels to do His work? it’s stated in the scriptures that Michael cast out the fallen angels. So, if it’s good enough for God to rely on St. Michael, it’s good enough for us.
http://www.kingjamesbibleonline.org/Bible-Verses-About-Archangel-Angel-Michael/