Prayerlessness is a sin because: (1) it causes us to forfeit some of God’s precious gifts to us, (2) it makes us much weaker when tempted, (3) it causes us anxiety, and (4) it closes our ears to God.
Moore, B. (2014). A WOMAN’S HEART God’s Dwelling Place (p.118). Nashville, TN: LifeWay Press.