Ok, I understand.
Yes, there are indeed many Christian sects, and Christian sects have been murdering each other for centuries.
So have the non-religious devotees of government.
And so have bad-tempered individuals living alone on the moors and in the hills.
Now, when you say "the world's oldest Christian Church", you're taking a side in an historical debate. There were divisions in the early Church, and there are still today. This is nothing new. However, one of the important early divisions was the one that became the Catholic one, and that was calling itself "catholic" before the end of the first century.
Some early Christians trod the path of which you speak, but theirs is not the "oldest Christian church". It is as old as its Catholic twin, born at the same time. So, when you suggest that the Catholic church is "newer", that is not true. Likewise, when you point to "the language of Jesus", that makes two assumptions. One is that Jesus had only one language. There's no very good reason to believe that. The other is that one particular language is holier or more authentic than another. And there's no basis to believe that at all.
It is fine to have your religious preferences, and if you want to take up the cause of one of the very earliest Christian sects, nobody is going to stop you. However, you overstate the case when you call it "older" and the Catholic "newer". They were siblings, born at the same time. And the one grew and took over the Earth, and the other did not have the same growth and career. That difference in relative success may say something about the will of God, or it may say nothing at all about it.