The passage from Romans to which I believe your letter refers, speaks of the habits of Temple prostitution of the various cults which flourished in Paul's days. These cults encouraged sexual licentiousness and sexual acts, which were as abnormal to heterosexuals as would be heterosexuality to those of us who were created homosexual or asexual. I encourage you to study this passage carefully with the assistance offered by modern theologians who are attempting to clarify those texts which have previously been subject to doubtful translation. We do not try to justify any sin, nor do we judge any person, for it is the sole prerogative of God to judge each and every person. Only God can decide whether our thoughts, words and willingness is centred on our own pleasures or on obedience to God's command to live lives which reflect our love for God and for all humanity.
Sin is sin, there are no big sins neither are there small sins.
Sin is lack of obedience to God's law of love. I do not believe this site attempts to promote any other definition of sin, nor do we encourage any to sin. God love each of us, and each includes all homosexuals.