What is the reason for the discontinuation of devoutness in prayer and contemplation of the Holy Quran despite perseverance in acts of obedience and righteousness?

Sins and transgressions, such as uncontrolled mixing and backbiting, deprive a servant of the sweetness of worship and bequeath him desolation. One must repent immediately and resolve not to return [to sin], and regret the sins; then the sweetness of worship will return. Weeping during recitation of the Quran or prayer is not necessary; rather, what is more important is to ponder the Quran and understand its meanings, along with reading a concise exegesis and asking Allah for humility and contemplation.