"The People of the Book ask you to bring down for them a Book from the sky. Certainly they asked Moses for [something] greater than that, for they said, ‘Show us Allah visibly,’ whereat a thunderbolt seized them for their wrongdoing. Then they took up the Calf [for worship], after all the manifest proofs that had come to them. Yet We excused that, and We gave Moses a manifest authority." Quran 4:153
as salam alaikum
The Qur'an says: "Allah forgives not that partners should be set up with Him but forgive anything else" (4:48). However many people who were mushrikin became Muslims and Allah forgave all their past sins. One of the interpretations of the above-mentioned verse is that as long as you are associating something with Allah, you won't be able to go back to Him through tawbah while it is possible if you are committing other sins.
With prayers for your success.