The Bible says in the book of Deuteronomy that homosexuality is an abomination, i.e. a sin. So are gay marriages immoral? To those who believe the Word of God is truth, the answer should be a firm, resounding YES! To those who question or just don't believe in God or His Word, the answer is either "no" or "it's debateable".
My answer is based on God's Word: Gay marriages are immoral, period. And that's my final answer