And blessed are the Gentiles, they of whom the prophet has written for behold, it it so be that they shall repent and fight not against Zion, and do not unite themselves to that great abominable church, they shall be saved for the lord God will his covenant which he has made unto his children and for this cause the prophet has written these things. (2 Nephi 6:12)
For with the heart one believes and is justified, and with the mouth one confesses and is saved.  For the Scripture says, "Everyone who believes in him will not be put to shame."  For there is no distinction between Jew and Greek; the same Lord is Lord of all, bestowing his riches on all who call on him.  For "everyone who calls on the name of the Lord will be saved."
 But how are they to call on him in whom they have not believed? And how are they to believe in him of whom they have never heard? And how are they to hear without someone preaching?  And how are they to preach unless they are sent? As it is written, "How beautiful are the feet of those who preach the good news!" (Romans 10:10-15 (ESV)
I just wanted to put these two side by side. The Bible says one is saved by faith that comes from hearing the Gospel, that Jesus Christ has died for your sins, and was raised from the dead. That is it. The Book of Mormon? No, salvation here is dependent upon choosing the right church! And yet there is nothing here that tells you what church is what. You are just told to avoid the great abominable church. (I happen to read some 19th century anti-Papism here, possibly the bias of a Congregationalist named Spalding. More on that later.) One is left wondering which one is the great abominable Church? Catholics? Lutherans? Presbyterians? Methodists? Congregationalists? LDS? I mean there is only one holy, catholic and apostolic church, which is not identified with any denomination, but consists of all believers in Christ who have heard the Gospel, and believe it, or as the Lutheran Confessions say, the sheep who hear the voice of their shepherd and listen to him. But there are many different earthly institutions that call themselves church. Which one particularly am I to avoid? Which one is THE Great Abominable Church? How would I know?
You see the question really shouldn’t be what church. The question that needs to be asked when you go to a new church is: is the Gospel preached here? Does it administer the sacraments according to Christ’s institution? In other words, does this Church teach what the Bible teaches? Lutherans, quite frankly, believe that there are Christians where ever the Gospel sneaks out despite all human efforts to the contrary. We consider all churches that believe in the Triune God to be Christian, and believe that it might even be possible for there to be Christians in other church bodies that don’t believe in the Triune God. Because being a Christian is really about whether or not you have heard the Gospel and believe it or not. That isn’t to say that doctrine doesn’t matter. It does. There is no excuse to go on teaching false doctrine especially after it has been shown to be false. Likewise we would not expect someone to stay in a church they are convinced is teaching false doctrine. Could there be Christians in the LDS church? Who am I to say? I have heard people say they had been convicted of the Gospel long before they were led to leave the LDS. I hold out hope that a few people I know who died members of the LDS church if only nominally, are yet saved after they had heard the Gospel. But I don’t know.
On the flip side I also believe it possible for you to be a member of the most orthodox church on earth and still not be a believer. Not that I second guess anyone’s confession, I can’t see in their heart. Their faith is between them and God. If you say you are a believer I have no reason to doubt you are. And if you believe Christ died for your sins, then you have no reason to doubt your salvation either. (I say that because of some abominable doctrines out there that actually teach their adherents to question whether they have faith or not.)
The point of all this is, when it comes to salvation, what church (as in denomination) you belong to is pretty irrelevant. What you believe is what is important. The question is do you believe Jesus Christ, the God/Man, has died for your sins. Of course, if you believe that you will probably want to join a church that teaches that. No Christian wants to support false doctrine with their time and money. But at times they might out of ignorance, or the possibility that there is not a church in their area that doesn’t teach false doctrine on some level, but their church at least believes in the Triune God, and preaches the gospel once in awhile. They should not feel like they are going to hell for attending there.