What Catholics believe is summarized in the Nicene Creed, which is given below.
We believe in one God,
the Father, the Almighty,
maker of heaven and earth,
and of all that is seen and unseen.
We believe in one Lord, Jesus Christ, the only Son of God, eternally begotten of the Father, God of God, Light of Light, true God from true God, begotten, not made, one in being with the Father.
Through Him all things were made.
For us men and for our salvation, He came down from heaven: by the power of the Holy Spirit
He was born of the Virgin Mary, and was made man.
For our sake He was crucified under Pontius Pilate; He suffered, died, and was buried.
On the third day He rose again according to the Scriptures; He ascended into heaven
and is seated on the right hand of the Father. He will come again in glory to judge the living and the dead, and His kingdom shall have no end.
We believe in the Holy Spirit, the Lord, the giver of life, who proceeds from the Father and the Son.
With the Father and the Son He is worshipped and glorified. He has spoken through the prophets.
We believe in one holy catholic and apostolic Church. We acknowledge one baptism for the forgiveness of sins. We look for the resurrection of the dead, and the life of the world to come. Amen.
Abortion - At the time of conception, a human person with a soul is created. Ending the life of that human person is murder, at all stages of development from conception to birth.
Apostolic succession - Believe in the Apostolic succession: ordinations dan all be traced back to St. Peter.
Attitude towards each other - The church considers Protestants to be Christians, but possessing only part of the truth.
Authority within the church - Vested in the hierarchy of the church.
Baptism - Sacrament which regenerates and justifies. Usually done in infancy.
Bible, status of - Historically teaches that the original writings by Bible authors are inerrant.
Bible, content - The church includes the same 66 books in the Bible as do Protestants plus the books of the Apocrypha.
Birth Control - All forms of birth control are morally wrong with the exception of Natural Family Planning.
Church, structure - Hierarchial.
Clergy, selection of - Appointed; all male; unmarried.
Euthanasia - Morally wrong.
Hell - More than a physical place, hell is a state of being involving "the pain, frustration, and emptiness of life without God."
Homosexuality, nature of - In most cases a homosexual orientation is not chose and thus is not, in itself, sinful.
Homosexuality, behavior - Morally wrong.
Immaculate Conception of Mary - Required belief.
Infallibility of the Pope - Required belief in matters of religious doctrine and faith.
Lord's supper/Eucharist - A sacrifice. Christ's body and blood are physically present and are consumed by believers.
Mary's status - The Mother of God. Mary's status is below Jesus', but above that of the saints.
Non-Christian religions - Have some value for the truth that they contain.
Prayer - To God. Also may ask Mary or a saint to intercede on their behalf.
Purgatory - A state of being in which souls are cleansed by purifying punishments before they can enter heaven.
Sacraments - The means of grace.
Salvation, achieving - Dependent on faith, works and sacraments. Is lost when a responsible person commits a mortal sin. It can be regained through repentance and the sacrament of confession.
Salvation among non-Christians - It is possible that those outside the Roman Catholic Church can be saved in spite of the errors in their religious beliefs.
Same-sex "marriage" - Against the natural law. Morally impossible.
Truth - Found in the scripture, as interpreted by the church. Also found in church tradition.
Virgin birth (actually virgin conception) - Required belief.