- why do you worship Mary whilst God forbids the worship of idols…
No catholic has ever worshipped Mary, ever. To do so would be idolatry.
The problem here is that said questioner probably belongs to one of those sects that is so devoid of liturgy that they think that prayer in all forms is adoration and that music and a sermon are the source and summit of christian worship. It’s sad, really.
- Why is the Pope infallible when only God is infallible as the Pope is human…
Christ tells the Apostles, “he who hears you, hears Me, he who rejects you, rejects Me.” He tells us that the Holy Spirit will guide the church into all truth. He tells us that the apostles, and specifically Peter, have the authority to bind and loose. Christ tells the apostles that just as the Father sent Him, so He sends the apostles. We are told by St Paul that the church is the pillar and bullwark of truth. All of these state one thing: that the church established by Christ speaks with His authority and is therefore infallible.
Why is the Pope infallible? Because God told us, even in the scriptures, that the church is protected from teaching error by virtue of the fact that those who hear the teaching voice of Peter (ie, the pope, speaking from the office of St Peter) hear the very teaching voice of God. The pope, being the steward-head of Christ’s church, teaches with the authority of the church and therefore with the authority of God when teaching on matters of faith and morals.
This person probably thinks that we consider the pope to be impeccable (without sin), which is not the case. We think that the pope speaks with the authority of Christ when speaking ex cathedra (in the limited cases that this can occur) precisely because this is very clearly stated by the Bible.