Can a Christian lose their Salvation?

I have been thinking a lot about Salvation lately, and the ability of one to "lose" his or her Salvation. I must begin with this: I used to firmly believe that one could very easily lose their Salvation if they did not live a "good" life. As long as they continued to "re-dedicate" their lives to Jesus, it would be okay again. Then I got saved. For a while I still held on to the idea, but with many lingering doubts as to the validity of the argument; "As long as you are IN CHRIST you will be saved". Then, the more i read my Bible, the more things started to work themselves out. 2 Corinthians 5:17 states, "Therefore if anyone is in Christ he is a new creation; the old has gone, the new has come!" So, when a person becomes "saved", they "die" to themselves, and are created anew to live for Christ. They are created ANEW! How can we still dwell on our sinful desires when God has created us anew? Once a person is saved, they should hate the things they once loved (the world and its devices) and love the things they once hated (God, the Word, fellowshiping with other believers, and the Church) One cannot come to Salvation in steps over time. You are either a Christian, or you are not. You are either alive, or you are dead. There is no "mostly dead", or "mostly alive"! You are or you are not. I have heard the line (or lie if you prefer), " He's almost a Christian. He just needs to take that final step." WHAT?! Excuse me?! The devil is "almost a Christian" as much as you or I were in our unconverted state! And just how many steps are there to become a Christian anyway? 5 simple steps? 4 Spiritual laws? Or can a person (though he HATES God) still walk toward Him, and when he feels like it "accept" Him? Do we think so little of the wondrous power of God that we reduce Him to such trite, and pathetic views? Who is this God? Does He have white hair, a big bushy beard, and sit upstairs just waiting so desperately for us to accept Him? Santa Clause in heaven, perhaps. IDOLATRY!!! You have broken the first and second commandments!
How about this one, "You're still a Christian, you just need to start acting like one again!" Yes.Yes. You are still a Christan. Colossians 2:20 says, "Since you died with Christ to the basic principles of this world, why, as though you still belonged to it, do you submit to its rules"? I will agree that a Christian can fall into sin, even for a season, but is their life characterised by their sin? No. Are they habitually continuing to sin, looking for opportunities, and planning to sin? No. But for those whose lives ARE characterized by their sins, HOW DARE YOU CALL THEM A CHRISTIAN!!!!! They talk, dress, tell jokes, watch movies, t.v. shows, have sexual relationships like the world and you think they are a follower of Christ?! "Put to death, therefore whatever belongs to your earthly nature: sexual immorality, impurity, lust, evil desires, and greed, which is idolatry. Because of these, the wrath of God is coming. You used to walk in these ways, in the life you once lived. But now you must rid yourselves of all such things as these: anger, rage, malice, slander, and filthy language from your lips. Do not lie to each other, since you have taken off your old self, with its practices and have put on the new self, which is being renewed in knowledge in the image of its Creator." Colossians 3:5-10.
Who are you to say that one can become saved and then walk away from the faith, only to become saved again? If that were so then the Bible is telling a lie when, in Hebrews 6:4-6, it reads," It is impossible for those who have once been enlightened, who have tasted the heavenly gift, who have shared in the Holy Spirit, who have tasted the goodness of the Word of God and the powers of the coming age, if they fall away, to be brought back to repentance, because to their loss they are crucifying the Son of God all over again and subjecting Him to public disgrace." And in Hebrews 11:26-28, " Then Christ would have had to suffer many times since the creation of the world. But now He has appeared once for all at the end of the ages to do away with sin by the sacrifice of Himself. Just as man is destined to die once, and after that face judgement, so Christ was sacrificed once to take away the sins of many people; and He will appear a second time, not to bear sin, but to bring Salvation to those who are waiting for Him." Maybe you should really pour over the book of Hebrews for a while. Jesus said, " It is finished", in John 19:30. Does he have to die again?
If you think that a person can walk away from their Salvation still, then you think that you are just as powerful as He is. How can I say that? Who has the power to change a man? You? No! God alone!! When you are saved He creates a new creature from the old. If your sinful self has died to sin, then it is dead. Duh. If you think you can still walk away, you are able to have to power (the same as God's) to resurrect your old self to live in sin, and when it is convenient, "come back" to Him again. So do you have the same life-changing ability as God who is the Creator of all? Do you? Well?! If you answered yes, you are a flat-out worshiper of an idol you call God!
Why am I being so harsh? Because I am tired of people living their lives the way they do and still calling themselves Children of God! This thinking has to stop! Open your eyes people!!!We can be confident of this, "that He who began a good work in you will carry it on to completion until the day of Christ Jesus." If we are truly saved, we will hear our Master's voice, and we will know Him. And most importantly, He will know us.

Some reading for you:
Matthew 7:21-23
Ephesians 5:1-16
Hebrews
The Gospels
The New testament
The Bible