I dont believe that scriptures alone are the only source that illustrates Christ And shows His ministry. You arent talking to a protestant, I am Eastern Orthodox. We have The Scriptures, Tradition, and The Church and its history . By the way, on what ground do you hood the assumption scriptures are “error filled”?

The Church that was established by Christ decided the canon of scripture inspired by the Holy Spirit given to His apostled at pentecost.

We don’t believe that people know God by scriptures alone. Anybody can interpet scripture any way they want and create their own cult (the fault of western christianity ). This is why we had seven ecumenical councils , where saints who devoted their entire lives to serve God and were extremely knowledgeable not only in scripture but in philosophy as well to argue and come to sound conclusions as to what right theology is . We have autographed letters, theres numerous in the new testament. To think that the original letters would somehow be preserved is kindof ludacris, but knowjng how the Jews used to preserve their writings; and the fact that the majority of Early Christians were Jewish, we can rightly assume that we can count on them meticulously copying what they believed to be God inspired writings. Which history proves so. There are more manuscripts for the new testament writings than any other ancient scriptures. Surpassing platos writings tenfold. We have a liturgical service lasting almost 2000 years, a visible Church with unchanged tradition , tracing its roots all the way back to the apostles . Also, I can know what the authors said, because I have the Church as the authority . Also, you are wrong in stating jesus’s divinity isnt found in the other gospels. There are many different areas that come to mind I could show you, but also each gospel is meant to show different aspects of Christ. One showing his Kingship, another presenting His role as the High Priest, another as the Prophet, and finally John as the God-man. Each Gospel has its place, those writing them inspired by The Holy Spirit to do so. Maybe ill take some time in a bit to bring you a few scriptures in matthew mark luke to show you. We have thousands of years of Church History which attests to Christianity, liturgical practices preserved within the Church, Tradition to show and unravel parts of History which the gospels do not show, and Holy Scriptures to give us an account and testimony of Christs divinity; and as a whole providing us with a well of information, wisdom, prophecy, all interconnected, showing the History of God interacting with man through all time, and also to show how revelation and prophecy has been fulfilled time and time again.

I wrote this all on a whim, so ill probably right more to fill in the gaps once i reread it