It is not "my" definition.
Perseverance of the saints, as well as the corollary—though distinct—doctrine known as "Once Saved, Always Saved", is a Calvinist teaching that asserts that once persons are truly "born of God", or "regenerated" nothing in heaven or earth "shall be able to separate (them) from the love of God" (Romans 8:39). -
Eternal Security
Thanks Felix, I just wanted to make sure we're talking about the same thing.
"Eternal security" is often seen as synonymous with "Perseverance of the saints." That is, a person who truly trusts in Christ, may have assurance of eternal life with God, and thus be eternally secure. Historically, this comes from a biblical, Calvinistic framework, wherein salvation is secure because the perseverance of the saved person is certain.
Today, however, the doctrine of eternal security is usually expressed without the reference to the perseverance (or continuance) and other means of grace indicative of true saving/justifying faith. This mind-set goes hand-in-hand with the "easy believism" and "carnal Christianity" so prevalent in the evangelical church today. It is characterized by the trite phrase "once saved, always saved", suggesting that one may continue in a life of willful sin and be confident of salvation because he has made a profession of faith in the past. This goes against biblical exhortations, warnings for final salvation and qualifications of true saving faith. For example :
John 15:6 "If anyone does not abide in Me, he is thrown away as a branch and dries up; and they gather them, and cast them into the fire and they are burned."
Heb 12:14 "Pursue peace with all men, and the sanctification without which no one will see the Lord."
Eph 5:5-6 "For this you know with certainty, that no immoral or impure person or covetous man, who is an idolater, has an inheritance in the kingdom of Christ and God. Let no one deceive you with empty words, for because of these things the wrath of God comes upon the sons of disobedience."
1 John 2:3-4 "By this we know that we have come to know Him, if we keep His commandments. The one who says, "I have come to know Him," and does not keep His commandments, is a liar, and the truth is not in him;"
1 Cor. 10:1-6 "For I do not want you to be unaware, brethren, that our fathers were all under the cloud and all passed through the sea; and all were baptized into Moses in the cloud and in the sea; and all ate the same spiritual food; and all drank the same spiritual drink, for they were drinking from a spiritual rock which followed them; and the rock was Christ. Nevertheless, with most of them God was not well-pleased; for they were laid low in the wilderness."
2 Cor 13:5 "Test yourselves {to see} if you are in the faith; examine yourselves! Or do you not recognize this about yourselves, that Jesus Christ is in you--unless indeed you fail the test?"
James 2:14-17 "What use is it, my brethren, if someone says he has faith but he has no works? Can that faith save him? If a brother or sister is without clothing and in need of daily food, and one of you says to them, “Go in peace, be warmed and be filled,†and yet you do not give them what is necessary for their body, what use is that? Even so faith, if it has no works, is dead, being by itself."
Definitive wandering is deadly and maybe a sign that one is not truly saved. Christians in the bible are warned and encouraged over and over again to not give up, but to persevere in faith in order to be saved. "Blessed is the man who remains steadfast under trial," as James says, "for when he has stood the test he will receive the crown of life, which God has promised to those who love him." (James 1:12)
http://www.theopedia.com/Perseverance_of_the_saints