Still pondering the wonder of the new birth and how it shows me I'm secure in my salvation:
Because of the new birth, we are permanently new creations and can't ever go back to the "old man." We now have, as part of our spiritual DNA, the imperishable divine Life of God. In fact, we are so united with the life of God that our spirit and His Spirit are ONE. Being inseparably one with eternal Life like that, we'll never die. But there's more good news..we have been made new creations with not only the very Life of Christ as our life, but also with the very nature of Christ as our nature!
We have only one nature - Christ's nature. The old sin nature that we had passed away; all things - ALL things, think of that! - have become new. So our nature is new, and only new, and the only nature we have is new - it's the nature of Christ Himself, who is our life. Just as we have the characteristics of our earthly parent, so we have the characteristics of our heavenly Parent - His life, His immortality, His nature!
We have been made "partakers of the divine nature" and this nature is a righteous, holy, loving, good nature. There is nothing in our new selves, our real selves, that wants to sin. Our new nature loves holiness, loves God the Father, loves other people, and always wants to do what is right! That is such a relief to me to know I'm not bad or evil or rebellious against God. I used to be an enemy of God in my mind, but now my spirit, my true and real self, is a friend and lover of God who always wants to follow His ways. Jesus said, "My sheep hear My voice, and they know Me, and they follow Me." Isn't that a comfort, to know we will follow Him? And why? Because it is our very nature to do so. We wouldn't want to do anything else. When Satan does tempt us and we fall, that is why we feel so bad about our failure - because it's not our nature to want to sin or to do sin! It's not our nature to fear, doubt God, rebel, be self-centered, or pull away from the Lord! It's our nature - the very nature of Christ in us - to say "I delight to do Your will." that is such a comfort to me!
We have a righteous nature, and that's the only nature we have. So we are fit for heaven because we are righteous with the righteous nature of Christ as our nature! You can't get any more righteous than that! And we didn't become that way through our hard work, efforts, or willpower: we were RE_BORN that way and thus will be permanently that way. It's just another characteristic we have as new creations! We're re-born as righteous, not unrighteous, people! We're newly made as not sinners any longer but as saints. The sinner man is gone forever and the saint man is here forever. The saintly, righteous new creation that God has made doesn't want to leave Him, fall away, turn from Him, or walk off and leave Him.
So often I've been afraid that I'd leave God and that I'd lose my salvation. I didn't see how set in stone my salvation really is - because of the new birth, my nature is wholly changed. I am now a person who doesn't ever want to leave God! And that is my permanent condition, because the new birth is a permanent thing that can't be reversed. So I never have to fear that I'd leave God. There is a verse in Hebrews 3 that says to see that you don't have an evil and unbelieving heart in departing from God - did you catch that? People who aren't yet saved have evil and unbelieving hearts. They have hearts that are rebellious and depart from God. Believers have have a new heart and new nature! Our hearts are good and righteous and believing hearts! Our hearts are not rebellious - we hear Jesus' voice, know Him, and follow Him! We won't depart from God! We cling to God and love God with all that we are, and want more than anything to please Him. So we can rest assured that we won't fall away or walk away or depart from Him. We really can't go against our very nature, which is the nature of Christ Himself in us. Christ would never leave God, so neither will we. Whew!
God showed me a very special promise from His Word that says this very thing. It is such a comfort ot me: it's in Jer. 32:40 - " I will make an everlasting covenant with them that I will not turn away from them, to do them good; and I will put the fear of Me in their hearts so that they will not turn away from Me." Isn't that wonderful? God not only promises that He would never turn away from us, He also promises that we will never turn away from Him. He has given us a new heart that fears (awes, revers) Him and so won't turn from Him, ever, NEVER! What a relief..
What a wonderful thing that God has wrought in us in the new birth! It shows me how safe and secure I am as His new creation child!