Does the Orthodox church believe in the Trinity?

Of course they do. They wouldn't be Christian otherwise.

Yes they do. As amatter of fact, the trinity is created form the orthodox beleif.

Yes.

Yes, it is.

Yes they do.

@ jurgen, we all know that Mohammad did not sacrifice anything but FORCED others (even muslims) to sacrifice for him. He forced his own son Zaid to sacrifice his wife Zaynab, so he could get naughty with her.

Why is Original sin there in islam?

while you're talking third and 4th century, specific the "early" church believed interior the trinity. i dont think of Paul taught the trinity. and im especially valuable the 1st century "saints" beleived interior the godhead. in particular via fact of psalms 80 two:6 there has continually been basically one God. i might upload (for planet earth) and for the earthlings and people, there is basically one saviour. nonetheless many are observed as.

Absolutely. We adhere faithfully to the Nicene Creed, which is Trinitarian to the core.

Blessings.
/Orthodox

Then why did you say "No" if you didn't know for sure?

Yes, but not the same as Catholic Trinity.

Orthodox Trinity does not give co-equality of God persons.
The Father is greater than the Son, the Holy Spirit came from the Father.Filioque is heresy.
Jesus sacrifice was not for atonement of original sin.