Sacred Scripture condemns homosexuality as an act of "grave depravity- (Catechism of the Catholic Church, 2357). There is no evidence in Scripture of homosexuality being mentioned in a positive manner. The Books of Genesis, Leviticus, and Romans all provide examples of God's condemnation of homosexual activity. Genesis demonstrates God's displeasure with the cities of Sodom and Gomorrah. Due to the contemptible homosexual demands made on Lot's guests, God destroyed both cities.
"They called out to Lot and asked, Where are the men who came to stay with you tonight? Bring them out to us!' The men of Sodom wanted to have sex with them at dawn the angels tried to make Lot hurry. Quick!' they said. Take your wife and two daughters so that you will not be killed when the city is destroyed'- (Genesis 19:1-29).
In the verses of Leviticus God speaks with Moses and is very explicit in condemning homosexuality. God forbids homosexual practices and makes the prohibition, "You shall not lie with a male as with a woman; such a thing is an abomination- (Leviticus 18:22). This disapprobation is repeated in a later chapter in Leviticus, which states, "If a man has sexual relations with another man they have done a disgusting thing, and both shall be put to death. They are responsible for their own death- (Leviticus 20:13). In the New Testament, St. Paul cites that indulgence of same-sex lust and the perverse actions of women with women, and men with men results in punishment that, "they deserve for their wrongdoings- (1 Romans 1:26-27). It is incredibly evident through these Scriptural passages that God does not condone acts of a homosexual nature. The Catholic Church's beliefs are grounded in God's wisdom upon the issue.
Under no condition does the Church approve of same-sex marriage, having strong convictions that it is contrary to God's plan for matrimony. Marriage is holy and sacred in the eyes of the Church, while same-sex unions are contradictory to the, "moral law- (Catechism of the Catholic Church, 2357).