"If I make it to Heaven..." These tragic words break my heart every time I hear them. If. If I make it. It's just one step down from the Satanic lie that you simply won't.
A better way to phrase this is "if Jesus takes me". This is a more accurate statement. "If I make it" assumes you're the one responsible for getting there. But of course, you're not. Whether or not you get to Heaven has exactly nothing to do with your own effort. In fact, on your own, you are guaranteed not to make it to Heaven.
But the good news is you're not on your own. It's not about you. Heaven is not a reward for your good works, and lack of bad works. It is a gift from the Lord, accepted through faith. And so the question isn't "am I good enough to make it?", but "is He good enough to bring me?" And the answer to that, my brethren, is a glorious yes!
Because salvation depends on God, not us, we can be as sure of our salvation as we can be of God's grace. There is no "if", but "when". If you believe in the name of the Son of God, you can know you have eternal life, just as surely as if you were already in the Kingdom.
An objection you always hear to this is that it opens the door to unrighteousness. After all, if I'm going to Heaven anyway, why not enjoy my life with as much sin as my heart can handle? There are two concurrent answers to this, the first being that it is actually the conditional view that has this effect, not the Eternal Security view.
Think about it: There are only two possibilities if Conditional Security is correct. Either you gain salvation, lose it and it's gone forever (and we only need to look at the irredeemable Satan and his forces to see what that does to us), or we can lose it, yet earn it back. If we can earn it, lose it, then earn it again, the only real fear we have is dying during those periods when we've lost it. Yet you often hear of Catholics, for example, sinning on the Saturday, confessing on the Sunday, then waiting until Saturday to repeat the process. Conditional Security becomes an excuse for exactly that. I can sin and lose my salvation, but it's no issue because I can get it back again.
But the more powerful answer is that such a faith is completely dead. If you believe that Christ died for you, you're probably not going to take that like a spoon full of sugar. It should have been me on that cross. My sins made that necessary: someone had to face punishment for them. Am I to spit in His face by letting Him take that punishment for me only to go right back to what made me worthy of punishment again? Who takes a bath only to nose dive straight back into the mud before their hair has even dried? Paul says it best in Romans 6:1-2 when he says "What shall we say then? Shall we continue in sin, that grace may abound? God forbid. How shall we, that are dead to sin, live any longer therein?"
Sinless perfection is unattainable in this life. It's a lovely thought, but it is nothing more than a fantasy at this point. In fact, in 1 John 1:8, John tells us "If we say that we have no sin, we deceive ourselves, and the truth is not in us." All of that to say that if you could lose your salvation, you would lose your salvation. But John continues: "...these things I write to you, so that you may not sin. And if anyone sins, we have an Advocate with the Father, Jesus Christ the righteous. And He Himself is the propitiation for our sins..." (1 John 2:1-2a, emphasis mine.)
All of this to say that real faith ultimately leads to real repentance. If I believe I am going to Heaven, I don't believe I am free to sin, but that I am free from sin. It's not "I am free to make this evil choice, since I won't go to Hell for it", but "I am free to make the right choice, since Jesus paid for every wrong choice I ever made." Sin is not strong enough to stop Jesus bringing you to Heaven, but through Jesus, you are strong enough to stop sin from ruling you.