What is the consecrated life?
The Consecrated Life, deeply rooted in the example and teaching of Christ the Lord, is a gift of God the Father to his Church through the Holy Spirit. By the profession of the evangelical counsels the characteristic features of Jesus — the chaste, poor and obedient one — are made constantly "visible" in the midst of the world and the eyes of the faithful are directed towards the mystery of the Kingdom of God already at work in history, even as it awaits its full realization in heaven. (Vita Consecrata, Pope John Paul II)
Code of Canon Law on Religious Life
Can. 573 §1. The life consecrated through the profession of the evangelical counsels is a stable form of living by which the faithful, following Christ more closely under the action of the Holy Spirit, are totally dedicated to God who is loved most of all, so that, having been dedicated by a new and special title to His honor, to the building up of the Church, and to the salvation of the world, they strive for the perfection of charity in the service of the kingdom of God and, having been made an outstanding sign in the Church, foretell the heavenly glory.
§2. The Christian faithful freely assume this form of living in institutes of consecrated life canonically erected by competent authority of the Church. Through vows or other sacred bonds according to the proper laws of the institutes, they profess the evangelical counsels of chastity, poverty, and obedience and, through the charity to which the counsels lead, are joined in a special way to the Church and its mystery.
Can. 574 §2. Certain Christian faithful are specially called by God to this state so that they possess a special gift in the life of the Church and contribute to its salvific mission, according to the purpose and spirit of the institute.
Can. 577 In the Church there are a great many institutes of consecrated life which have different gifts according to the grace which has been given them: they more closely follow Christ who prays, or announces the kingdom of God, or does good to people, or lives with people in the world, yet who always does the will of the Father.
Catechism of the Catholic Church on Religious Life
Religious life derives from the mystery of the Church. It is a gift she has received from her Lord, a gift she offers as a stable way of life to the faithful called by God to profess the counsels. Thus, the Church can both show forth Christ and acknowledge herself to be the Savior's bride. Religious life in its various forms is called to signify the very charity of God in the language of our time. (CCC, 926)