I have not encountered Church of Christ people before doing so on this forum, so I haven't seen the need to investigate it until now. However, I always heard that they believed that baptism is necessary for salvation. Just that in itself is attacking an essential doctrine of the Bible - that Jesus ALONE SAVES. He is the Alpha and the Omega and everything in between. He Himself IS SALVATION. Simeon, in the temple, took the baby Jesus in his arms, and prophesied, "Now Lord, You are releasing Your bond-servant to depart in peace, according to Your word. FOR MY EYES HAVE SEEN YOUR SALVATION, which You have prepared in the presence of all peoples, A Light of Revelation to the Gentiles, and the Glory of Your people Israel." Luke 2:29-32 Jesus IS SALVATION both to the Gentiles and the Jews. It's Jesus plus NOTHING, not baptism, not good works, not being Jewish, not having wealth or power - ABSOLUTELY NOTHING. The C of C (Church of Christ) presents a different way, a distorted way, to be saved, which according to Paul, is a different gospel. Galatians 1:6-9 Paul said "he is to be accursed" (whoever preaches this distorted gospel). I don't know how the C of C can be categorized as anything but a cult.
As if that wasn't enough, some C of C assemblies believe that you can't even be saved, unless you're in their church, which is what you encountered as a teenager. That too is, at least, cult-like. I understand that each C of C assembly or congregation is autonomous, i.e. they have no higher governing authority over them. The plurality of elders in each church is their governing authority. So it's likely that some C of C churches will not totally agree with everything in another C of C.
Then you throw in - no musical instruments or candles or incense during church. Also you must have communion every Sunday and it must be accompanied with a meal. The Sunday near or on Christmas or Easter must not be different than any other Sunday - i.e. no excessive mention of those holidays. A successful outreach is measured by how many were baptized, NOT by how many were saved.
So now we have a lot of legalism, which is NOT a good fruit of the Spirit.
By the way, I retired from delivering mail on June 30, 2022, from the Denver Post Office - 38 1/2 years.