The Roman Catholic Church is often confused with true biblical Christianity. Many distinct and serious differences exist between the two entities. What are the teachings of the Roman Catholic Church that distinguish it from biblical Christianity? Lengthy books have been written on this subject, but as an overview some of the differences in doctrine are outlined below with Scripture references to validate the biblical teaching. 
The differences are great and for the most part the Catholic Church would fall into the false religion category. This analysis is not intended to offend good Catholic people, but rather to point out how vastly different the true Gospel of Jesus Christ is from the gospel of Rome. It is up to each individual to study what they are being taught in light of the Bible, God’s inerrant Word.
Roman Catholicism Teaches:
The Bishops, with the Pope as their head, rule the universal church.
God has entrusted revelation to the bishops.
The Pope is infallible in his teaching.
Scripture and tradition together are the Word of God.
Mary is the co-redeemer, for she participated with Christ in the painful act of redemption.
Mary is the co-mediator, to whom we can entrust all our cares and petitions.
Initial justification is by means of baptism.
Adults must prepare for justification through faith and good works.
Grace is merited by: good works.
Salvation is attained by cooperating with grace through faith, good works, and participation in the sacraments.
No one can know if he will attain to eternal life.
The Roman Catholic Church is necessary for salvation.
Christ’s body and blood exist wholly and entirely in every fragment of consecrated bread and wine in every Roman Catholic Church around the world.
The sacrifice of the cross is perpetuated in the Sacrifice of the Mass.
Each sacrifice of the Mass appeases God’s wrath against sin. The sacrificial work of redemption is continually carried out through the sacrifice of the Mass.
Christ, the head of the body, rules the universal church (Colossians 1:18).
God has entrusted revelation to the saints (Jude 3).
God alone is infallible (Numbers 23:19; Acts 17:11).
Scripture alone is the Word of God (John 10:35; 2 Timothy 3:16-17; 2 peter 1:20-21), Mark 7:1-13).
Christ alone is the Redeemer, for He alone suffered and died for sin (1 Peter 1:18-19).
Christ Jesus is the one mediator to whom we can entrust all our cares and petitions (1 Timothy 2:5; John 14:13-14; 1 Peter 5:7).
Justification is by faith alone (Romans 3:28).
God justifies ungodly sinners who believe (Romans 4:5). Good works are the result of salvation, not the cause (Ephesians 2:8-10).
Grace is a free gift (Romans 11:6).
Salvation is attained by grace through faith apart from works (Ephesians 2:10).
The believer can know that he has eternal life by the Word of God and the testimony of the Holy Spirit who indwells believers (1 John 5:13; Romans 8:16).
There is salvation in no one but the Lord Jesus Christ, “for there is no other name under heaven that has been given among men by which we must be saved” (Acts 4:12).
The bread and wine are symbols of the body and blood of Christ, and He is bodily present in heaven (1 Corinthians 11:23-25; Hebrews 10:12-13).
The sacrifice of the cross is finished (John 19:30).
The once-for-all sacrifice of the cross fully appeased God’s wrath against sin (Hebrews 10:12-18).
The sacrificial work of redemption was finished when Christ gave His life for us on the cross (Ephesians 1:7; Hebrews 1:3).
No amount of self-punishment or efforts can atone our sins. Our sins have already been punished fully in the body of Jesus. Only His finished work satisfies God. One must let go of the false teaching that God needs our help to wash away your sins. Jesus alone is the propitiation for our sins.
In many instances the doctrines of the Catholic Church were slowly adopted over many years as various popes issued decrees. In most cases, the doctrines are not even based on Scripture, but on a document of the church. Most Roman Catholics consider themselves to be Christians and are unaware of the differences between their beliefs and the Bible. Tragically, the Roman Catholic Church has championed that ignorance by discouraging personal study of the Bible and making the people reliant on the priests for their understanding of the Bible, which is the direct opposite of what the Holy Bible teaches, not the altered Catholic “bible.” God commands us to study his Word and correctly interpret it.
“These were more fair-minded than those in Thessalonica, in that they received the word with all readiness, and searched the Scriptures daily to find out whether these things were so” (Acts 17:11).
“Be diligent to present yourself approved to God, a worker who does not need to be ashamed, rightly dividing the word of truth” (2 Timothy 2:15).