BTW: Lucifer is an angel. Angels don’t go through any process of “convincing,” of themselves or other angels. Angels have no psychological processes akin to our. What an angel chooses, he chooses with a glaring, clear vision of the truth, and with a totality of commitment of the will, that a human cannot begin to imagine.
B.S. Lucifer convinced a third of God’s angels to rebel with him against God. If Lucifer had “a clear vision” of the Truth, he would have know he would lose his battle with God.