How is Personal Prayer Important for Spiritual Growth?

St Paul urges us to "pray constantly" (1Thes 5:17), but to make progress we must- first, foremost and always - set aside regular private time for personal prayer. Every spiritual master in the history of the Church has taught that holiness begins and ends in personal prayer - even if we participate in public liturgies or other group prayer - we will never draw close enough to the Lord.
Private, personal prayer is the way we open ourselves to grace by unmasking our hidden nature and revealing our true selves to God. In silent prayer we grow in faith. We are transformed.
 In this context, I would like in particular to recall and recommend the ancient tradition of lectio divina: the diligent reading of Sacred Scripture

accomspanied by prayer brings about that intimate dialogue in which the person reading hears God who is speaking, and in praying, responds to him with openness of heart.The ultimate goal of personal prayer is mystical union with God.