How does neglecting prayer lead to spiritual backsliding?

Ryle relates that neglecting private prayer is one of the primary causes of backsliding in the Christian life. When believers stop praying, they risk losing connection with the source of their strength and guidance. Just as physical neglect leads to illness, spiritual neglect can cause a Christian to falter in faith and ethics, leading to a potential downfall. Moreover, a life void of prayer can lead to a coldness in one's heart towards God, distancing them from the vital relationship needed for spiritual vitality.