Doctrine
Grace is the free and undeserved gift that God gives us to respond to our vocation to become his adopted children. As sanctifying grace, God shares his divine life and friendship with us in a habitual gift, a stable and supernatural disposition that enables the soul to live with God and to act by his love. As actual grace, God gives us the help to conform our lives to his will. Sacramental grace and special graces are gifts of the Holy Spirit to help us live out our Christian vocation.
Grace
From the creation story in Genesis, the Church has learned that humanity was originally created in a state of holiness and justice and that the first ancestors of the human race lost this state for themselves and all humanity by their sin ("original sin"). Christ is called the "second" or "new Adam" because he ushered in the new creation by forgiving sin and restoring humanity to the grace of God's friendship lost by original sin. 
Creation of Man
Angels are spiritual, personal, and immortal creatures, with intelligence and free will, who glorify God without ceasing and who serve God as messengers of his saving plan. Scripture mentions nine choirs of angels and the church teaches that each person has a guardian angel.
Creation of Angels
Virtues are habits of right behavior. We receive the theological virtues of faith, hope, and charity at Baptism. They have as their aim to unite us to God through Jesus Christ. Saint Paul says charity is the most important of the three because without charity faith and hope are imperfect.
Theological Virtues
Justification is the gracious action of God which frees us from sin and communicates "the righteousness of God through faith in Jesus Christ." (Rom.3:22) Justification is not only the remission of sins, but also the sanctification and renewal of the interior person.
Justification
An indulgence is the remission before God of the temporal punishment due to sin whose guilt has already been forgiven. A properly disposed member of the Christian faithful can obtain an indulgence under prescribed conditions through the help of the Church which, as the minister of redemption, dispenses and applies with authority the treasury of the satisfactions of Christ and the saints. An indulgence is partial if it removes part of the temporal punishment due to sin, or plenary if it removes all punishment.
Indulgences
The Holy Trinity is the mystery of one God in three Persons: Father, Son, and Holy Spirit. The revealed truth of the Holy Trinity is at the very root of the Church's living faith as expressed in the Creed. The mystery of the Trinity in itself is inaccessible to the human mind and is the object of Faith only because it was revealed by Jesus Christ, the divine Son of the eternal Father.
The Holy Trinity
The ultimate end of the whole divine economy is the entry of God's creatures into the perfect unity of the Blessed Trinity. Even now we are called to be a dwelling place for the Most Holy Trinity: "If a man loves me," says the Lord, "he will keep my word, and my Father will love him, and we will come to him, and make our home with him." (Jn 14:23)
The Indwelling of the Holy Trinity
Through an utterly free decision, God has revealed himself and given himself to man. This He does by revealing the mystery, His plan of loving goodness, formed from all eternity in Christ, for the benefit of all men. God has fully revealed His plan by sending us His beloved son, our Lord Jesus Christ, and the Holy Spirit.
The Greatness of God
This gift of God begins with the "life" of faith and the "new life" in Baptism, is communicated in sanctifying grace, and reaches perfection in the communion of life and love with the Trinity in Heaven.
Life Everlasting