Let’s talk about having right doctrine:
“But even if we or an angel from heaven should preach a gospel other than the one we preached to you, let them be under God’s curse!” - Gal 1:8
Christian Theology is also a subset of Christian Doctrine. Basically put, Christian Doctrine is what the church of Jesus Christ believes, teaches, and confesses on the basis of the word of God. “Doctrine”, when mentioned in the New Testament, includes teaching about both confession and conduct, both theology and ethics. And the Gospel is a subset of Christian Doctrine. Paul in this verse expresses strong resistance to any other Gospel than what he preached to the Galatians. However, there is a lot of Christian Doctrine out there that, as it turns out, is not essential for salvation. Even doctrine straight from Paul.
“Paul declares his own prophecy and inspiration to be essentially imperfect (1 Cor. 13:9, 10, 12; cf. 1 Cor. 12:10; 1 Thess. 5:19-21). This admission justifies a Christian criticism even of his views. He can pronounce an anathema on those who preach ‘a different gospel’ (Gal. 1:8, 9), for what belongs to simple faith, the facts of salvation, are absolutely certain. But where prophetic thought and speech go beyond these facts of salvation, wood and straw may be mingled with the gold, silver and precious stones built upon the one foundation.” - N.T. Beyschlag
There is a difference between doctrines that are essential for salvation and doctrines that make a person “Orthodox”.
You don’t have to believe all that is Orthodox to be saved. But learning which beliefs are needed for salvation are both simple and take a lifetime to master. Paul here, in Galatians, is saying that the Gospel of Jesus Christ based on faith and not works is one of those doctrines that is essential for salvation.
What about you? What doctrines do you believe are essential for salvation? Which ones do you think are necessary for one to be orthodox? Which beliefs are good to have by you don’t think matters very much? What hills are you willing to die on?
Pelikan, Jaroslav. The Christian Tradition, A History of the Development of Doctrine, Vol 1.: The Emergence of the Catholic Tradition (100-600) (Pg. 1-2). The University of Chicago Press
Strong, Augustus. Systematic Theology (Complete - Volume 1, 2 & 3 of 3) (pp. 129-130). BZ editores. Kindle Edition.
The Theology Program. Introduction to Theology: Course #1 of the Theology Program (Pg. 89). Credo House Publishers.