I grew up in the Catholic church but then I converted to Protestantism. When I converted I discovered the true love for Christ, and I started changing my lifestyle. For the first time I felt hungry to learn about God's Word, and it also made me into a better person. The only problem is that I discovered that they are somewhat Calvinists. I'm not sure if they are 5 point Calvinists, but I do not believe that Jesus only died for the elect. They teach that those who believe in Jesus were predestined by God to believe in Jesus. I'm not saying they are a bad church. The people there are wonderful people, and they are very nice and treat me well. Their preaching is excellent and they have many great ministries. I have been struggling with this. I really feel comfortable there and it is also very close to my house. It is more accessible to me because I'm still learning how to drive. Should I stay there? Or should I look for another church? I don't think they are trying to deceive people, I just think they have a couple of misinterpretation of the word of God. They also teach "once saved, always saved." Do these teachings necessarily mean that it is a bad church? They do not teach that "once saved, always saved" gives you a license to sin.
It is difficult when you grow in your knowledge of the Lord and then realize that the church that help lead you to this point isn't all that it should be. Most people whom I've met in the denominations are generally good people, sincere in what they believe, but sadly wrong about their beliefs.
It is God, not man, who sets the standard for what we must believe. You and I are not in the position to tell God what He should accept.
Good works and sincerity aren't going to save someone who is going against God's teachings. "Not everyone who says to Me, 'Lord, Lord,' shall enter the kingdom of heaven, but he who does the will of My Father in heaven. Many will say to Me in that day, 'Lord, Lord, have we not prophesied in Your name, cast out demons in Your name, and done many wonders in Your name?' And then I will declare to them, 'I never knew you; depart from Me, you who practice lawlessness!'" (Matthew 7:21-23).
God doesn't want His teaching altered. "I marvel that you are turning away so soon from Him who called you in the grace of Christ, to a different gospel, which is not another; but there are some who trouble you and want to pervert the gospel of Christ. But even if we, or an angel from heaven, preach any other gospel to you than what we have preached to you, let him be accursed. As we have said before, so now I say again, if anyone preaches any other gospel to you than what you have received, let him be accursed. For do I now persuade men, or God? Or do I seek to please men? For if I still pleased men, I would not be a bondservant of Christ" (Galatians 1:6-10).
In any church you are going to find some with a small variance in what they think God said. That is because people are learning and growing and everyone is not at the same point. But when it comes to points that are being taught as "this is what the church here teaches" and they are at variance with what God said, well, then there is a problem. "But why do you call Me 'Lord, Lord,' and do not do the things which I say?" (Luke 6:46).