Let’s take the opposite arguement for a second. Ok, so the Pillar and Bulwark of Truth can teach error and be incorrect. Now then, if this is true I have several questions. First, when does God let us know it is wrong? Is it a matter of personal revelation? Will a new prophet appear (like Mohammid)? Second, when the Chruch is in an era of being wrong, are all of the people that follow it due to faith in Jesus’ prayer that we all be one and whoever hears his representatives hears him (Luke 10:16) doomed to hell? What about when the Church is right? Are those who think that it is wrong doomed or saved? Let’s look back at Luke 10:16. If we hear those sent by Christ, we hear him, if we reject them, we reject Christ. If they are going to speak for Christ, will he not protect them from teaching error? How does the idea of a fallibile Church line up with the Church being one body in Christ? Can the head be correct and the body wrong? Am I missing the entire point? God has the ability to raise his Son from death, create the entire universe with thought alone, and know everything from the beginning to the end and back again, yet he would not protect the Church from errors in teaching? There are a lot of verses that point to an infallibile Church and as much logic that says it must be as well. If Scripture and human reason point to the same answer, then can it be wrong?