In Mark 16:16, our Lord tells us: “whoever believes, and is baptized, will be saved, but whoever does not believe will be condemned”. However, in this statement there is a hidden question – “What exactly are we to believe”? if we go to the end of Matthew’s gospel our Lord is quite specific, and tells us that we are to believe everything - everything He taught the Apostles. “Then Jesus said, “All authority … teaching them to obey everything I have commanded you… (Matthew 28:18-20, and Mark 16:15).
If the apostles were commanded to teach us everything, then it is reasonable to expect that we are to believe everything they proclaim to us, Christ made it clear that we are to listen to them. He said: “He who hears you hears Me, he who rejects you,… (Luke 10:16; Matt. 10:40)
From the foregoing discussion we see that to be saved we must believe everything that Christ taught. Consider some things Protestants do not believe. They do not believe in the Real Presence of Christ in the Eucharist (John 6: 40-59; 1 Corinthians 11:23-29), they reject five of the seven sacraments that Christ instituted, including confession (forgiveness) of sins in the manner Christ prescribed (John 20: 19-23, and 2 Corinthians 5:18-12). They do not believe in Purgatory, even though Purgatory is well documented in both the Old and New Testament… etc. While they may claim to be believers, in reality they are only partial believers.
In general, Protestantism is based on numerous violations of scripture. For example, private interpretation of scripture is one of the principle tenets of Protestantism, but the Bible condemns such private interpretation. See: 2 Pet 1:20; 2 Peter 3:15-16. Also see: 2 Thessalonians 2:15; Galatians 1:8-9; 2 John 1:9-11; Acts 20:28-30; 2 Timothy 4:3-4; Revelation 22:19, and Deuteronomy 4:2, and Proverbs 30:6; Galatians 1:8-9; 2 John 1:9-11; Acts 20:28-30; 2 Timothy 4:3-4.
Objectively speaking, it appears that these non-believing “believers” will not be saved (Matthew 7:13-14). Notice I said objectively speaking. In the end, only God knows what a person understands. Most Protestants believe what they believe, because this is what they have been told, or taught all their life, and they have never made an in-depth study of scripture to verify the correctness of what they have been taught. So they may not be totally responsible for the errors they believe.
In any case, I would ask the following question. “Why take a chance on a man-made church, a man-made system of theology that for the last 500 years (from the time of Martin Luther) has produced one error upon another, an accumulation of hundreds of errors that has splintered into thousands of Protestant churches, teaching ideas that were never taught by the early church, or the apostles” (Galatians 1:8-9; 2 John 1:9-11; Acts 20:28-30; 2 Timothy 4:3-4)?
If we are to be saved, we must accept all of Christ’s teachings, not just the ones we like. We cannot be cafeteria Christians – picking and choosing what we will believe or not believe. We cannot be Burger King Christians – having it our way. The last thing we should want to do, is leave this life singing “I Did It My Way”.