All forms of reverent address to God are included. Since the command is to pray without ceasing, therefore, failure to pray is a sin. The blessedness of prayer and the necessity to pray cannot be underestimated. Wilful absence from Church Prayer Meeting implies that we care little for the spiritual welfare of our brethren and for ourselves. Such prayerlessness is a sin.
Corporate prayer is necessary for spiritual vitality and revival.
As children of God, we are in an ongoing warfare against the adversary. Our enemy is Satan, with his hosts of fallen angels. The realm of this warfare is spiritual, invisible to the naked eye. When a believer does not feel like praying or sees no need to meet together for prayer, he is capitulating to the wiles of the Devil. He is trying to fight a spiritual battle with the arm of flesh.