Contemplative prayer is the prayer of the child of God, of the forgiven sinner who agrees to welcome the love by which he is loved and who wants to respond to it by loving even more. But he knows that the love he is returning is poured out by the Spirit in his heart, for everything is grace from God. Contemplative prayer is the poor and humble surrender to the loving will of the Father in ever deeper union with his beloved Son.
Source: Catechism of the Catholic Church (Vatican.va)