The issue concerning any church and its practices should be “Is this biblical?” If a teaching is Biblical (taken in context), it should be embraced. If it is not, it should be rejected. God is more interested in whether a church is doing His will and obeying His Word than whether it can trace a line of succession back to Jesus’ apostles. Jesus was very concerned about abandoning the Word of God to follow the traditions of men (Mark 7:7). Traditions are not inherently invalid…there are some good and valuable traditions. Again, the issue must be whether a doctrine, practice, or tradition is Biblical. How then does the Roman Catholic Church compare with the teachings of the Word of God?
Salvation: The Roman Catholic Church teaches that salvation is by baptismal regeneration and is maintained through the Catholic sacraments unless a willful act of sin is committed that breaks the state of sanctifying grace. The Bible teaches that we are saved by grace which is received through simple faith (Ephesians 2:8-9), and that good works are the result of a change of the heart wrought in salvation (Ephesians 2:10;2 Corinthians 5:17) and the fruit of that new life in Christ (John 15).
Assurance of salvation: The Roman Catholic Church teaches that salvation cannot be guaranteed or assured.1 John 5:13 states that the letter of 1 John was written for the purpose of assuring believers of the CERTAINTY of their salvation.
Good Works: The Roman Catholic Church states that Christians are saved by meritorious works (beginning with baptism) and that salvation is maintained by good works (receiving the sacraments, confession of sin to a priest, etc.) The Bible states that Christians are saved by grace through faith, totally apart from works (Titus 3:5;Ephesians 2:8-9;Galatians 3:10-11;Romans 3:19-24).
Read more: http://www.gotquestions.org/Catholic-Biblical.html