There is the gospel of Jesus (his parabolic speech about the Kingdom of God) and then there is the gospel of Christ (what Jesus became to the church after he died).
I believe that God is revealed in the person of Jesus. To me, that's Christianity.
Instead of requiring "true" believers to give their assent to a list of ancient, outmoded beliefs from ancient times, we need to realize that a follower of Jesus needs to pick up their cross and follow him.
Anyone, anywhere, anytime can claim belief in theology like "born of a virgin," "Savior of the World," etc. It's no moral skin off anyone's nose to do that.
The Gospel is about what Jesus actually accomplished in his life, death and resurrection.
In his life he fulfilled all of the demands of God's Holy Law. In our name and on our behalf he offered to God the Father a life of perfect obedience to his Holy Law.
In his death he put to death the old sinful Adamic race and in doing so destroyed sin, death and the devil.
In his resurrection he brought forth a new humanity. perfected it and took it to heaven.
As God's new Adam and our new humanity we can now stand before God's holy court as justified.