Is it wrong to teach in a denomination?

Answer:

Throughout Acts, we find the apostle Paul teaching in Jewish synagogues (Acts 9:20; 13:5,14; 14:1; 17:10; etc.). Paul did that because he had an audience interested in God, though they did not follow God correctly. Paul often focused on proving that Jesus was the Christ in his teachings. "Now when they had traveled through Amphipolis and Apollonia, they came to Thessalonica, where there was a synagogue of the Jews. And according to Paul's custom, he went to them, and for three Sabbaths reasoned with them from the Scriptures, explaining and giving evidence that the Christ had to suffer and rise again from the dead, and saying, 'This Jesus whom I am proclaiming to you is the Christ'" (Acts 17:1-3). This is what apologetics is: "reasoned arguments in justification of something."

One of the many reasons denominations stray from the Scriptures is that few practice presenting reasoned arguments. Ideas are accepted solely because this is what they desire. Proving an idea is desirable to God is too much effort (and often shows the idea is wrong).

Thus, I see nothing wrong with teaching an interested group various aspects of truth so long as it doesn't interfere with your worship with the brethren.