That church — Christ’s church — is the Christian church, not the Catholic church. It is my church, and your church. As believers and followers of Christ, we can both rightly claim to be members of the body of Christ.
Like I said, lineage doesn’t make a difference to me, as we both trace the origin of our faith to the same point. We divided, but our origins and lineage are the same to the point of division. One can dispute, I suppose, whether the division was a heresy or a divinely inspired separation ... but I would claim the latter.
I cannot believe in the infallibility of any human being or human organization, as it conflicts with the established doctrine of original sin. Humans are inherently fallible, and no Biblical passage gives me reason to believe that any infallibility rests in a man or a hierarchy. Such would be putting faith in a man or group of men rather than the Almighty.
SnakeDoc
However, if the same authorities declare, say, that Mary is the Mother of God, as in fact happened at the Council of Ephesus in AD 431, then I must give assent, for defining the Faith in such vein is part of their authentic charism, it is protected from error by the Holy Spirit, and is therefore infallible. The individual men who formulated the definition were all sinners, and therefore not infallible at all regarding their personal conduct. But, within the parameters that are needed to be put in place to make sense of Matthew 28:20, John 16:13-15, and the like, these men exercised "infallibility" in authentically interpreting the true doctrine involved. I would, therefore, be required to give my assent of faith to their decision. And I do. So should you. Perhaps you do already, and you can thank the Council of Ephesus for that. Scripture alone done not answer the question very well regarding issues involving "persons," "natures," "essences" and the like, as they pertain to Jesus. Scripture alone is somewhat ambiguous at, at best. As such, it was a legitimate question to figure out: did Mary give birth to God, or only to Jesus' human nature? "Theotokos" is what they came up with to describe how she fit into the equation: she was the "God-bearer." Amen to that!