So in other words the men that developed the tradition decide if it is from men or God?
The men who follow them decide if they believe them or not. I believe the Holy Catholic Church because I can verify she teaches me the truth. I can compare the teaching of today's Catholic Church with the Holy Scripture, and with the historical evidence, and see consistency. I can compare the moral theology of the Church and see its validity according to the natural law of reason. I alos see the Catholic moral theology courageously defended by my Church, often alone against the corrupt world filled with supposedly Christian sects.
I also can see the deception of Protestants, the mean interest these sects have been catering to since Hus and Luther, and see how Protestantism does not square with the Holy Scriptutre in its foundational teachings. I observe fake prophets show up like mushrooms after a rainy day all over the Protestant dreary landscape. I see their followers uncapable of a sustained argument strictly over the scripture: they give fantastical explanations to plain text or they run off, or they insult my Church on some unrelated matter so that to change the topic. I decide therefore that they are all charlatans and people fooled by charlatans. It is not complicated.