Some Catholics have confused biblical perspectives: those who place undue emphasis on Mary, for example. Jesus was divinely conceived, Mary was not. She was never perfect: she was a sinner like every human that ever lived except Jesus. She did not remain a virgin after the birth of Jesus and had no reason to do so. There is no reason for anyone to pray to Mary or bow to her since she cannot answer prayers and is not deserving of any special adoration (bordering on idolatry). Most important, Mary has nothing to do with anyone's salvation. Only Jesus can to that. There are Bible verses to back every single one of these points, none for the beliefs that some Catholics seem to have about Mary.
And that's just one issue. The same can be said about the Eucharist, chaste priests, praying to saints, the papacy, and other topics. IIRC, others have cited scriptures on these things above.
“Incline my heart to your testimonies, and not to selfish gain!”
Psalm 119:36