I agree what Classimami said, that if you follow the word of God, and your church denomination followed the Word of God, and everything that is believed in that denomination is backed up with the Bible, then that is the true church. I strongly believe that the Seventh-Day Adventist denomination is the true church, because the beliefs are based on the Bible and nothing else. Many other denominations have their own Bibles that they follow which is tailored to their religion.
Another poster said that if God knows your heart, then it shouldn't matter. Well, the Bible did say that if you didn't know something, God will not hold it against you, he will "wink" at your ignorance, but the Bible also said that if you know the truth, and you continue to do the wrong thing, it wll be held against you.
If any of you have not heard of the Seventh-Day Adventist religion, we are a denomination where our Sabbaths are from sunset Friday to sunset Saturday (the Bible says that the evening and morning were the first day). We believe that Saturday is the Seventh Day even though most other denominatios claim that it is Sunday. If you look back into history, the Catholic Church took responsibility for the "change" in the Sabbath Day, and claimed that they changed the Sabbath Day for their denomination, but mostly all other denominations followed.
I'm not here to say that only this denomination will be in heaven, for the bible says that many denominations will be in heaven, and that some people followed the Bible to the best of their knowledge. But I want to encourage everyone to not take what the preacher says for granted. Look it up for yourself....search the word. There are many people in the world that just go to church just to go, and believe everything that they hear. If you didn't search the word for yourself you could be believing the wrong things.