Once you accept Jesus as your personal Lord and Savior and are saved, are you always saved?

“Love the Lord with all your heart, and with all your soul,

and with all your MIND”--Matt 22:37

Question:  Once you accept Jesus as your personal Lord and Savior and are saved, are you always saved?  That is, can you lose your salvation? 

This question is a corollary to the "Are Catholics saved?" topic. Many non-Catholic Christians profess this doctrine of "Once Saved, Always Saved" (OSAS).  Indeed, the issue of soteriology (the doctrine of salvation) is a main point of contention among Evangelical Christians.  It is derived, I believe, from the Evangelicals' great love of Christ and His atoning work on the cross.  What Evangelicals object to is the notion that we must do anything to "earn' heaven.  It's ALL Jesus, all the time, in their paradigm.  God's forgiveness is sooo complete, sooo infinite, that the moment they profess their repentance, all sins, past, present and future, are forgiven.  Anything less than that indicates that Jesus' salvific gift is ineffective, to their way of thinking.
Catholics, of course, ought to give a hearty "amen!" to the Evangelical's "it's ALL Jesus" mantra.  And we ought to be humbled by their great devotion to the atoning work of Christ on the Cross.

Where the Evangelicals get it wrong with the OSAS doctrine is that they ignore all the Scripture verses which state that salvation is conditional.  We have a moral assurance of salvation, but not an absolute assurance.  Thus, if we sin, we can indeed lose our salvation.  The Bible speaks of this, well,  everywhere.
 
There is a significant number of Bible Christians who believe that you are saved through saying the "Sinner's Prayer".  Sometimes this is done through an altar call, in which people are called to make a public commitment to Christ.  While this practice ought not be denigrated--truly, many have started their beautiful walk with God because of this invitation-- some ironies do exist:

• the "Sinner's Prayer" is not found in the Bible
• an altar call is not found in the Bible
• typically there is no altar in the "altar" call, for most churches of this type eschew the notion of a sacrifice (it was done once and for all by Jesus and cannot be repeated).  Altars are missing from these churches because sacrifice is missing.  (The purpose of an altar, of course, is to offer up sacrifices.)

Again, I offer a disclaimer:  please read my presentation of what Evangelical Christians believe with the same healthy skepticism you would have if you heard a Protestant say, "Catholics believe _______"  Sometimes they get it right; more often than not they get it wrong.  At any rate, as there are over 30,000--and counting--different Protestant denominations it's really difficult to represent the Protestant position anyway.  Also, please note that I use the terms Evangelical Christians, Protestants,  Fundamentalists, non-Catholic Christians, and Bible Christians synonymously, although there are differences--but the distinctions are quite fluid.

(Actually, Catholics are Bible Christians, are we not?  We are the original Bible Christians!  )So with regard to the Evangelical's OSAS assertion, 'tis true that there are some verses in the Bible which seem to support their doctrine. There are, however, multiple Bible verses which proclaim that salvation is not a "done deal".  How do we reconcile this?  Because Catholics do not use Scripture alone to discern God's Revelation, we have the benefit of the other channel of God's Word:  Sacred Tradition.  And Tradition tells us what truths these Bible verses, in their entirety, profess.  We understand the Bible through the lens of the Faith which was handed down to us through the Apostles.

Finally, "if you can lose your salvation by sin, doesn’t that imply that you are earning your salvation? Ephesians 2:8–9, says, "for by grace you have been saved through faith; and this is not your own doing, it is the gift of God—not because of works, lest any man should boast."
...The New Covenant is not a system of works righteousness whereby a person can please God and earn heaven by doing a number of good deeds. This is what Paul is driving at in Ephesians 2. He is not saying that sin cannot separate us from Christ.

When he gave a litany of created things that can not separate us from the love of God in Romans 8:39, notice that he did not say, "neither fornication nor adultery nor drunkenness nor murder will separate us from the love of God." He was well aware that if we choose sin, we renounce Christ. In 1 Corinthians 15:1–2, Paul says, "Now I would remind you, brethren, in what terms I preached to you the gospel, which you received, in which you stand, by which you are saved, if you hold it fast—unless you believed in vain." So, you could believe, but fail to hold fast to the gospel, and not be saved (cf. 2 Pet. 2:20).

This is why Paul spoke in the book of Romans about the "obedience of faith" (Rom. 1:5, 16:26). It is not enough that one call Jesus Lord, for, as he said, "Not every one who says to me, ‘Lord, Lord’ shall enter the kingdom of heaven, but he who does the will of my Father who is in heaven" (Matt. 7:21; cf. Matt. 10:33, 18:35). If we are disobedient, God will "take away his share in the tree of life and in the holy city" (Rev 22:19).

Just because you may choose to no longer hold fast to what was freely given to you does not mean that you were ever capable of earning what was given to you in the first place. The same is true of earthly sonship—it cannot be earned. But if you were adopted, you would be free to run away as a prodigal son and lose your inheritance." source

I am trying to be cautious about my presentation of the (OSAS) teaching, lest I misrepresent this concept.  However, it would seem to lend itself to living a life of sin because "hey!  I'm saved!"  I suspect that most advocates of OSAS would deny that their belief promotes a life of sin.  (Just like it's a misrepresentation of Catholicism for objectors to state, "Catholics think they can live a life of sin because they can confess their sins the next day to a priest."  Either way is not a fair portrayal of one's beliefs.)  That being said, it does seem that there has been many an Evangelical Christian who has lived a dissolute life but feels his salvation is still guaranteed. 

For more in-depth study visit these websites:

Catholic Bible online

Catechism of the Catholic Church online

Catholic Answers Forums discussion on Once Saved Always Saved (OSAS)

"Always be prepared to give an answer to everyone who asks you to give the reason for the hope that you have. But do this with gentleness and respect" 

1 Peter 3:15