Ungodly beliefs are beliefs that do not align with God and His word.
“And they say, How doth God know? and is there knowledge in the most High? Behold, these are the ungodly, …” Psalm 73:11-12
With every ungodly belief, there are one or more sins attached. “All unrighteousness is a sin” 1 John 5:17.
A heart and mind that has not been healed or renewed harbour ungodly beliefs.
“…beloved, let us cleanse ourselves from all filthiness of the flesh and spirit, perfecting holiness in the fear of God.” 2 Corinthians 7:1