Christians sometimes meditate by thinking about small parts of the Bible, or by saying the words of a prayer to themselves over and over. Meditation is an expression of Christian prayer. In the Catechism of the Catholic Church is specified that by means of meditation "The mind seeks to understand the why and how of the Christian life, in order to adhere and respond to what the Lord is asking"; also it is pointed out that "meditation engages thought, imagination, emotion, and desire. This mobilization of faculties is necessary in order to deepen our convictions of faith, prompt the conversion of our heart, and strengthen our will to follow Christ".