He who becomes weak and falls, let him not postpone his repentance, lest he wallow more in sin and his determination become weaker. Also, let him not be ashamed, because of his sin, to offer his prayer to God in its appointed time, even if this were after falling into sin immediately, claiming that his mind and conscience have become defiled, and it would not be fitting for him to stand before God and lift up his hands to heaven. These, my brother, are demonic thoughts, with which the devil dominates you through his cunning, so that you may not run away from him quickly.

—H.E. Metropolitan Youssef, How to Pray