I have no scriptural authority for the status of Mary in heaven and so I choose not to speculate on it. Are you saying that makes me a non-Christian?
And that would include the New Testament itself. Any Church which errs in Doctrine in one area could also err in another, no?
But if I tarry long, that thou mayest know how thou oughtest to behave thyself in the house of God, which is the church of the living God, the pillar and ground of the truth.
15 "The pillar and ground of the truth"... Therefore the church of the living God can never uphold error, nor bring in corruptions, superstition, or idolatry.