If God has spoken and the Bible is His Word, of what value is religion that is disobedient to the Bible?
Men use religion as a buffer between them and God. They want to be able to say in the day of judgment, "I was a faithful practitioner of my religion". Somehow they believe that this has some weight with God. The thing they don't seem to realize is that nothing has weight with God except Truth and integrity. God is a God of Truth and He measures everything by its standard. If a thing is true, He commends and supports it; if a thing is not true, He commits Himself to its destruction. This is true in all of the universe. Religion is included. If the religion is built off of falsehood (no matter how "well-intentioned"), God hates it. He is not impressed with the worship of what is false. So, since He has spoken and preserved what He had to say in the Bible over centuries, He knows that we have access to the Truth. It is not His fault if we ignore the Bible. If we stand before Him in ignorance of its teachings, it will not be because we have not had access to it.
Many of the children of men use the false appeal to their "sincerity". They say, if we are sincere, God will overlook our ignorance. The problem is that this is patently untrue. Sincerity is not a virtue in the pursuit of falsehood. Besides, it is impossible to be genuinely sincere and refuse to set aside time on a regular basis to study what God has said. The truly sincere are on a hunt for the Truth; they don't use sincerity as a buffer to keep them from guilt. And, on top of that, there is no evidence in the universe that sincerity makes any difference if we are wrong. A child who sincerely thinks he is immune from injury and toddles off of a high place will be injured because of God's law of gravity. Sincerity doesn't matter. A young adult who sincerely believes that the laws against drinking alcoholic beverages are not applicable to him/her is just as dead after the deadly car accident as the person who wasn't sincere.
The fact is that God doesn't honor sincerity. He honors Truth. The two are not necessarily connected. God honors only the Truth and He knows the genuinely sincere will not practice a religion that contradicts the Truth. He knows that men and women are so committed to their community standing that they will not change churches even when it becomes apparent that the one they belong to is not faithful to the Bible. He knows that men and women so committed to their traditions and their arrogant ideas (that they couldn't possibly be involved in a false religion) will not even subject their church's dogma to the scrutiny of the Scriptures.
A person recently asked me why I was so sure that my interpretation was more correct than those who differ with me. My answer was that there is no guarantee that my interpretation is more accurate; but the fact is most people don't have a different interpretation, they have no interpretation at all. They are not studying the Bible. Most people blow off what they don't want to accept by simply saying That's just his interpretation. But that doesn't deliver them from their liability for the truth.