I am a firm believer in eternal security. Personally, I base my belief in Jesus's words: "I give them eternal life, and they will never perish; no one will snatch them from my hand. My Father, who has given them to me, is greater than all, and no one can snatch them from my Father’s hand." I believe, "no one" would include myself also. Salvation is a gift given to us by God, and the Bible never even hints that he would take it back. Romans 8 is a classic study on that.
However, I do not believe in the Free Grace flavor of this important doctrine. I hold to the traditional, Reformed view. Free Grace teaches that assurance of salvation is solely based on the promises of God's Word, and not on our righteous living. The traditional view teaches that righteous living, along with the promises of the Bible, is a sign of sure salvation. Though I believe a Christian can be carnal, I believe one needs to examine herself, particularly if she has no desire whatsoever for righteous living.
So, I really believe in Perseverance of the Saints, doctrinally. But, I choose Eternal Security, as a term. Perseverance, to me, somehow sounds as if I am desperately clinging onto His hands. Eternal Security, as a term, sounds just right for me, especially when I take Jesus at his word.
Now, what is your take?