Can a Christian lose his/her salvation?
It really depends on whether you are Armenian or Calvin. The former says you can while the later says you can not.
Calvin argues on predestination, eternal security and the elect.
John 10:28 – eternal life
Ephesians 1:11 – predestination
1 Corinthians 1:8 – eternal security
Ephesians 1:7 – eternal redemption
Rome 8:38-39 – eternal love.
Armenians, in the other end, advocate on freewill and fore knowledge of salvation.
Matthew 7:21 – not every one who says to me Lord will enter the Kingdom of Heaven
Luke 8:13 – parable of the one who sows
Hebrew 6:6 – fall away from Salvation
1 Peter 1:10 – confirm your call so that you will not fall.
We must realize that we can not understand the all of the Bible. Christians as a whole has no problem with certain Biblical issues like salvation in Christ, Bible redaction and so on. But there are also issues no Christian can understand. These include Trinity, eschatology, supralapsarianism (a view that salvation was predetermined by God and can not be changed), etc.
Catholic, Lutheran, Presbyterian and Baptist are Augustinians, Lutheran and Calvin. Thus, they believe that believers will never, never lose one’s salvation. Evangelical, Pentecost and Charismatic are Armenians believing that believers may lose their salvation and be eternally lost.
Both views are Biblical and do not contradict each others. It is only a matter that we are seeing the issue in a different angle. One is a blind man feeling the body of an elephant and describes it as a wall. The other blind man touching the elephant tail and say elephant is like a bloom.