If there is no infallible interpretation of Scripture, or no other source of certain teaching, we wouldn't have certain knowledge of Christ's teachings. IOW, we wouldn't know with certainty what to have faith in.
We can know with moral certainty, through unaided human reason, that the Bible is the inspired Word of God, because we can know with the same moral certainty that the Catholic Church is the Church that Christ founded. Therefore, we can be morally certain that the truths of faith proposed by the Church for our belief, are worthy of our belief.
Keep in mind too that there are various degrees of Church teaching, from the lowest, theological speculation, to the highest, solemnly pronounced dogmatic teaching.
Sure we would because we have Scripture. There doesn't NEED to be infallible teaching on Scripture.
Besides, who is going to interpret THAT and how do you prevent fallible humans from misinterpreting infallible teaching on Scripture if they can't be kept from misinterpreting infallible Scripture?
Don't you need someone to infallibly interpret the infallible interpretation?
And so on, ad nauseum?
Having perfectly correct doctrine is not a requirement for salvation. Receiving, IOW believing in his name, Jesus is.
John 1:12-13 12 But to all who did receive him, who believed in his name, he gave the right to become children of God, 13 who were born, not of blood nor of the will of the flesh nor of the will of man, but of God.
The word translated *right* can also be translated *authority*.
Here, if you want to look it up.
Getting saved is simple. Staying saved is easier, because God guarantees it with the Holy Spirit.
Catholicism makes it too difficult with all the rules and regs and all the theology they claim you have to have nailed down just right or you're labeled as some kind of -ist heretic.