Oddly enough, religion can provide no reliable guidance that will help anyone figure out what behavior is moral or immoral.
Most religionists believe just the opposite. Many of them, or so I’ve read, are convinced that religion is the only reliable source of moral guidance. They’re convinced that atheists, who lack the guidance provided by religion, must be amoral monsters.
To understand why they have it backwards, we need only cast our eyes back through history at the Inquisition. During the Inquisition, which went on for hundreds of years, the clergy of the Catholic Church tortured and murdered untold thousands of innocent people.
Today, we have no trouble seeing that their actions were profoundly immoral. But that was not how it appeared at the time. At the time, the torture and killing were fully approved and supported by the highest levels of the Church hierarchy. Everyone (except possibly the people who were being tortured and murdered, and maybe a few of their friends) was convinced that the torture and murder were entirely in accord with the teachings of the Roman Catholic Church, which were, in turn, entirely in accord with what God and Christ expected of their worshippers. The torturers were sure that they were doing God’s own good work.
It is still, I understand, an item of Catholic doctrine that the Pope’s pronouncements on important matters of this sort are inspired directly by God and are therefore free of error. I wonder how the Pope would explain his predecessors’ enthusiastic endorsement of torture. Was the torture God’s will, or is the doctrine of infallibility simply wrong? There would seem to be no other options.
Be that as it may, the lesson should be clear: The fact that someone in authority in your church tells you that a given course of action is moral or immoral is not a valid reason to do or avoid doing anything whatever. The human authority in whom you put your trust may be mistaken, or worse.
Needless to say, written sources of guidance are no better. The Bible is full of internal contradictions and bizarre, outmoded teachings. Today the assumption is usually that those teachings are meant to be understood as metaphors or something of the sort. I’m not an expert on scriptural interpretation, but it seems obvious to me that in order to figure out which parts of the Bible are to be taken literally and which are to be understood in some other manner, you’ll need to consult a trusted human authority within your church. The Bible itself provides no guidance on such questions.
But as I noted a moment ago, the human authority whom you consult may be wrong — about scriptural interpretation or anything else. Ultimately, the only thing you can trust is your own conscience. When faced with a vexing moral dilemma, you should of course consult a variety of knowledgeable people and ask them for advice. If you’re religiously inclined, you would naturally want to consult people within your church. Because their view of the situation may be one-sided, however, you would also be well advised to consult a few people who are not members of your church, in order to get a broad variety of opinions.
You can choose to agree with what you’re told, or you can choose to disagree and act differently. But it’s still your choice. The fact that other people tell you to do, or avoid doing, a certain act does not and cannot absolve you of your own personal responsibility. That’s the point. Religion cannot be relied on to provide moral guidance.