You also ask:
Is it true that if you’re in a church that doesn’t follow Christ’s doctrine correctly or step by step, the whole church & congregation is accountable?
What’s the difference between the Church of Christ and all the other named churches?
Baptist Church, Methodist Church, Seven Day Adventist Church, Christian Centers and Non-denominational Churches?
In a church that doesn’t follow Christ’s doctrine correctly, the whole church & congregation is to some degree accountable. I would suggest that if you are in this situation, do your best to point out to the church the problems and attempt to resolve them. If this is not possible, I would suggest you find a church that does follow the teachings of Jesus correctly.
Wrong doctrine is a serious concern. Consider the following passages:
1 Tim 4:16
Keep a close watch on yourself and on the teaching. Persist in this, for by so doing you will save both yourself and your hearers.
1 Tim 6:3-5
If anyone teaches a different doctrine and does not agree with the sound words of our Lord Jesus Christ and the teaching that accords with godliness, (4) he is puffed up with conceit and understands nothing. He has an unhealthy craving for controversy and for quarrels about words, which produce envy, dissension, slander, evil suspicions, (5) and constant friction among people who are depraved in mind and deprived of the truth, imagining that godliness is a means of gain.
2 Tim 4:3-4
For the time is coming when people will not endure sound teaching, but having itching ears they will accumulate for themselves teachers to suit their own passions, (4) and will turn away from listening to the truth and wander off into myths.
Then I heard another voice from heaven saying, “Come out of her, my people, lest you take part in her sins, lest you share in her plagues; (5) for her sins are heaped high as heaven, and God has remembered her iniquities.
Your second question is difficult to answer as there is more than one “Church of Christ”. Here are some distinguishing features of some of the churches you mention.
- Baptism by immersion for professing believers as opposed to infant sprinkling.
- Quoting from Wikipedia
The United Methodist Church seeks to create disciples for Christ through outreach, evangelism, and through seeking holiness through the process of sanctification. With a focus on triune worship, United Methodists seek to bring honor to God by following the model of Jesus Christ, which is made possible by the power of the Holy Spirit. The flame in the church logo represents the work of the Holy Spirit in the world, which is seen in believers through spiritual gifts. The two parts of the flame represent the predecessor denominations, the Methodist Church and the Evangelical United Brethren, and are united at the base symbolizing the 1968 merger.
- Seven Day Adventists
- Believe that the seventh day (Saturday) should be observed as a Sabbath. Also hold in high esteem the writings of Ellen White, who they regard as a prophetess.
- Christian Centers
- Sorry, I’m not familiar with this church.
- Non-denominational churches
- Quoting from Wikipedia
In Christianity, non-denominational institutions or churches are those not formally aligned with an established denomination, or that remain otherwise officially autonomous. This, however, does not preclude an identifiable standard among such congregations. Non-denominational congregations may establish a functional denomination by means of mutual recognition of or accountability to other congregations and leaders with commonly held doctrine, policy and worship without formalizing external direction or oversight in such matters. Some non-denominational churches explicitly reject the idea of a formalized denominational structure as a matter of principle, holding that each congregation is better off being autonomous.