Thanks for your thoughtful reply.
It is the Church’s teaching on faith and morals that is infallible. You are correct that if a Catholic teaches pro-abortion, for example, we should know that is false. We know the Churches teaching on the sanctity of life.
However, there are other churches who teach this is not false.
>>>In my view the church does not exist as the “pillar and foundation of truth”
How do you view 1 Timothy: “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.”