Although it remains to be determined if homosexuality is a genetic, social or personal stigma, homosexual acts are condemned by God and can never be approved by the Church (1 Corinthians 6:9-10, Genesis 19:1-29, Romans 1:24-27 and CCC 2357). If homosexuals are born with the condition, then they are called to live a life of Christian purity and chastity for the greater love of Christ. Such people can experience a life of trial, which all others must treat with compassion and sensitivity.
The act of homosexuality is a “sin that cries to heaven for vengeance” (Gen 18:20) because it separates the unity of sex between two spouses from the procreative element which is necessary to legitimize and bless a marriage. Homosexuality is unnatural because it embraces lust between same-sex partners over the purity of love in a Christian marriage. The Church teaches:
Homosexual persons are called to chastity. By the virtues of self-mastery that teach them inner freedom, at times by the support of disinterested friendship, by prayer and sacramental grace, they can and should gradually and resolutely approach Christian perfection. (CCC 2359)