There is only one way for God to be with us, to abide with man: the gift of His grace. The prophets' sigh, begging the heavens to rend that God may come down, has been answered in Jesus Christ: He is the true temple, God's living presence in our midst. The one who loves the Son will be loved by His Father, and the Triune God will come to him to make their "abode" with him. Grace therefore brings about the mystery of the inhabitation of the Most Holy Trinity in the soul. This surpassing gift stands at the heart of the Christian life and leads us into eternal life, the happiness for which we were created. Hence, we must safeguard that divine life poured out upon us and seek to grow in it with the help of theological and moral virtues, alongside the gifts of the Holy Spirit. What a treasure a soul possesses, to be in the state of grace, that is, to be beloved of God and a lover of Him! In this little work, Fr. Lanzetta distills the teaching of Sacred Scripture on the mystery of grace, assisted by the great Fathers and Doctors of the Church-above all, St. Augustine and St. Thomas Aquinas-and in light of the Church's Magisterium. Grace is shown to be Christian theology's inner structure, opening up the understanding of Divine Revelation and enabling us to live according to its demands. So far from being metaphorical, ethereal, or obscure, grace is as real as our lives: it is the life of the soul, as the soul is the life of the body.