Denial is a strong aversion to the truth. When we deny Jesus Christ, we are sinning and there is rebellion, rejection, doubt, and unbelief in our heart.
We can deny Christ by not believing and living the truth of His word.
“Therefore whoever confesses Me before men, him I will also confess before My Father who is in heaven. But whoever denies Me before men, him I will also deny before My Father who is in heaven. Mathew 10:32-33