Romans 1:26-27 reads, “For this cause, God gave them up unto vile affections: for even their women did change the natural use into that which is against nature. And likewise also the men, leaving the natural use of the woman, burned in their lust one toward another: men with men working that which is unseemly, and receiving in themselves that recompense of their error which was meet.”I am certainly not a biblical scholar and claim utter ignorance when it comes to the New Testament. There are, however, some generally undisputed facts. Romans is actually Epistle to the Romans and it was written by Paul circa 60 CE. The purpose of religion is to provide a path to an afterlife and the purpose of Romans is to explain that the path is offered exclusively through the Gospel of Jesus Christ.
In short, follow the rules and you go to paradise when you die. Paul was an important figure in defining what those rules are. Around 50 CE Paul found himself in Asia minor with a number of obstacles to proselytizing. Converts would require some painful surgery and would have to give up foods that they had eaten their entire lives. Paul is responsible for changing the rules so that Christians do not have to keep kosher. Nor must they be circumcised. The point is that not all of the rules are meant to please Paul's god.
While I don't know much about the Bible I do know a thing or two about ancient Rome. I have recently read multiple works by scholars such as Mary Beard, Tom Holland and Robert Gravis.
There really were no gay people in Ancient Rome at least not in the way that we recognize sexual orientation today. It was perfectly acceptable in Roman society for men to have sex with men and boys as long as they were the “top.” It was a widespread practice in the middle and upper classes which made pretty slave boys a rare and expensive commodity. Presumably about 3% to 5% of the population of the Roman Empire was gay. However, because of the fact that homosexuality was acceptable, in at least one form, gay people went unnoticed. Publicly, citizens of the Roman Empire played the roles that they were expected to play. Their private indiscretions as gays and lesbians were less relevant than those roles. During Paul's lifetime, Romans had more important things to worry about including the reign of Emperor Nero who kept quite busy executing and torturing people. Nero set Christians on fire for outdoor lighting.
Therefore, throughout the Empire having homosexual sex was irrelevant to societal status. From obedient slave to consul, everyone had a well defined role to play. The role of women, by the way, was to be perpetually pregnant because of staggering childhood mortality rates. Paul certainly had no understanding whatsoever of gay people. The very existence of gay people would have been unknown to Paul. Paul's understanding was limited to the fact that people had homosexual sex.
This is the problem associated with slavish obedience to ancient chronicles. Trying to compare what is known through social and medical science now in contrast to what was known in ancient Rome is really no different than comparing what we know today about radiology or magnetic imaging or anesthesia for that matter. The predicate for following Paul's rules is willful ignorance of advances in knowledge over the last two thousand years.
So Obama is correct. We should celebrate diversity. LGBT pride is, in many cases, not so much pride but the absence of shame. We might never stop the shaming but, hopefully, some gay boy or girl in Alabama or Mississippi might feel a bit better about themselves because of the President's permission slip to be who they are.