In my studies of Catholicism I concluded that sin is what God does not want us to do because it is harmful to us.
Contemplating the consequences of our thoughts and actions from that point of view can be revelatory.
In considering acting or thinking outside of proscribed beliefs of right and wrong, keeping in mind the short and long term effects on ourselves, and of course others, is a deep examination of the nature of Love.
The missing piece from many concepts about manifesting with thought, intention, and visualization, is the two great Commandments.
Loving God above all else, with the whole self, and loving others by seeing that God self in them, and working from that foundation, manifestation is assured.