This coming Sunday we are going to deal with the number one killer of the Gospel of Jesus Christ: Legalism. The brand of legalism that Paul was addressing was not that of mere rules and regulations. Some could make a case that some “spiritual disciplines” are some what legalistic. Consider what I am saying here: If a person misses reading the Bible one morning or evening because he has been too busy throughout the day, he may feel as if he is out of favor with God. What happens if he forgets to pray before his meals on any given day – especially a Sunday? Then he will know that he’s lost favor with God. This is the type of legalism with which Paul is dealing. It is the legalism that says that Jesus Christ’s death according to the Scriptures, His burial and His resurrection according to the Scriptures is inadequate. In addition, this type of legalism says that even the enabling power of the Holy Spirit is inadequate because he couldn’t make this man read his Bible or pray before his meals.
What Paul the apostle is getting at is very simple: Anything that deviates from the sufficiency of Jesus Christ and His Holy Spirit is wrong and should be strongly opposed. It’s what Tullian Tchividjian said in the very title of one of his books: Jesus + Nothing = Everything. Conversely, Jesus + Something = Nothing! If one believes he loses favor with God every time he doesn’t hold to some rule or regulation, than Jesus Christ is insufficient and the man becomes enslaved to this type of legalism. Our worth is not based on what we do but rather on what Jesus Christ has already accomplished and finished for us.
Now this doesn’t give us license to sin and live our lives in such a manner that is sinful. Nor does salvation in Jesus Christ give us the right to be legalistic and try to force others to live according to the Law of the Scriptures or rules and regulations that supersede the Bible that we as men make up. What Jesus Christ accomplished for us gives us liberty to live our lives and not have the fear of being unacceptable to God. Paul says it this way:
“I have been crucified with Christ; and it is no longer I who live, but Christ lives in me; and the life which I now live int he flesh I live by faith in the Son of God, who loved me and gave Himself up for me. I do not nullify the grace of God, for if righteousness comes through the Law, then Christ died needlessly.” (Galatians 2:20-21)
Short, sweet, and to the point! Can’t get any better than that!
D.J. Gorena 
My understanding of the Scriptures is that a Christian cannot “fall from grace.” Romans 8:31-39 says that nothing can separate us from the love of God. In addition, everyone, whether saved or lost, is under God’s “common” grace. That is, it rains on the just and the unjust alike. Salvific grace is such that once a person is saved he is always saved.