The heresies common to virtually all Protestants are the so called sola scriptura and sola fide. The article explains that. There are many other heresies that some Protestant sects hold, and some don’t, not worth discussing here piecemeal.
Let's deal with sola fide -- first -- the Romans & Galatians epistle revelation that defeated the idea that self-justification was justifiable.
Excerpt from http://www.eefweb.org/sermons/topical/The%20Five%20Solas%20of%20the%20Reformation/Part%204%20-%20Sola%20Fide.htm:
The Catholic position in opposition to Luther’s Sola Fide was that the grace of God, by His good pleasure was poured into us. As this pouring or infusing occurred, it made us righteous and thus able to perform good works. Our free will cooperating with the grace then performed the works and together made us fit for salvation. It was taught that only by our will cooperating with grace and producing good works was the sinner able to merit salvation. Therefore, grace was infused and we cooperate with it to produce good works that belong to us. Those good works improve with time until they are such that we have pleased God enough to grant us salvation. Justification to the Catholic mind was then a process, not an event by declaration. Perhaps nowhere can the Roman Church’s rebellion against this doctrine be found any stronger than in the 1563 Council of Trent canons. We have already seen the authority of scripture, the lone Priestly role of Christ as Mediator and Redeemer. We have also seen that the way of salvation exists only because of the inestimable grace of God. Salvation would not exist had God in His mercy not provided a means for atonement and propitiation of His wrath. In evaluating Sola Fide, we shall see that the righteousness that the justified sinner stands in is not the works which by performing he has merited grace. Rather we will see that the only efficacious righteousness that will save us is being clothed with the righteousness of another—the righteousness of Christ imputed to us.
Of course, the Catholic position is the Scripturally off-base posture of synergism.
My Q to you: If you can't even confess "Jesus is Lord" in a culture of persecution, minus the Holy Spirit's power, how can you take credit for any other good work He does in and through you? (And why would you want to even try -- given the Scriptural reality that we're to glorify God in ALL that we do?)
RC's opinion of the bible is self explanatory.