You don't produce fruit to change your nature. You produce fruit because of your nature. Discover who you already are in Christ, and bear fruit without ceasing.
Start with something almost too simple to notice. A mango tree does not become a mango tree by producing mangoes. It produces mangoes because it already is one. The nature determines the fruit, never the other way around.
So here is the picture to carry with you. You are not an apple tree straining to produce mangoes in the hope of one day becoming a mango tree. You are already a mango tree, who simply needs to stop producing apples and start producing the mangoes you already are.
Fruitfulness is just the release of what your nature already holds. And unceasing means a condition has been created where that nature is released without hindrance. So today, let everything that has stood between you and the release of who you truly are begin to fall away.
Who you are by nature in Christ
Everything turns on this one verse, and on believing it even when your feelings argue.
Love has been perfected among us in this: that we may have boldness in the day of judgment; because as He is, so are we in this world.
1 John 4:17 (NKJV)
As He is, so are you, right now, in this world. We struggle with that mainly because we confuse spirit, soul, and body. Scripture says you are spirit, soul, and body. Your body and soul are your natural part, what you can see, taste, feel, hear, and smell. But your spirit is the unseen you, and there is no natural way to make contact with it. None. The only instrument for operating in the spirit is faith.
This matters enormously, because every fruit you produce as a believer is called the fruit of the Spirit. What is born of the flesh is flesh; what is born of the Spirit is spirit. And God is Spirit, so when you were born again, you were born again in your spirit.
That which is born of the flesh is flesh, and that which is born of the Spirit is spirit.
John 3:6 (NKJV)
So when God says as He is, so are you, He is speaking about your spirit. Can you see it, feel it, touch it? No. Is it true? Yes, because God said it. Which means the only place to learn what your spirit is really like is the word of God.
The mirror of the word
This is why the blessed man of Psalm 1 meditates on God's word day and night. He is fixing his mind on what God says he really is, bypassing what his eyes report and what his soul feels, and settling his thoughts on the truth about himself.
Abide in Me, and I in you. As the branch cannot bear fruit of itself, unless it abides in the vine, neither can you, unless you abide in Me.
John 15:4 (NKJV)
To abide in Jesus is to stay, in your mind, in who you are in Him, and to let His words stay in you until you actually believe it. From that place, fruit comes. So if you are not seeing fruit in some area of your life, it is often because you have not yet let the truth of who you are grip you. The word is a mirror; keep looking into it until you see yourself the way God does.
But be doers of the word, and not hearers only... For if anyone is a hearer of the word and not a doer, he is like a man observing his natural face in a mirror.
James 1:22-23 (NKJV)
James says the word is a mirror, but a strange one. When you walk away and forget what it showed, you go back to living by the face in the natural mirror, the anxious, guilty, defeated face. The blessed man is the one who keeps looking into the perfect law of liberty and does not forget. He lets the reflection of who he is in Christ define him, and then he acts on it.
Paul calls this the difference between being carnally minded and spiritually minded, and he does not soften it: to be carnally minded is death. When you relate to people and the world only by what you can see, judging them good or bad by appearances rather than by what God's word says, you are living in the flesh, and in the very moment you do, something in you dies. We no longer know anyone merely after the flesh. We once knew even Christ that way, but no longer. Now we know one another by the Spirit.
You are dead, and alive to Jesus
So who are you really? First, just like Jesus, you are dead. You died in Him and were buried with Him, which means you no longer live for yourself. The only life you now have to live is His.
I have been crucified with Christ; it is no longer I who live, but Christ lives in me.
Galatians 2:20 (NKJV)
That old I, the one that took over when Adam sinned, the self that treated God as an enemy, has been dethroned, displaced, destroyed. So you no longer have a nature that craves and desires sin. You are no longer a sinner by nature. When you still feel like one, remember the devil is a liar. Do not reckon by the natural. Keep counting the old I dead.
God is not counting your sins
Because that old rebel self has been dethroned, God was in Christ reconciling the world to Himself, not counting your sins against you. Notice the direction carefully. It was never God who needed to be reconciled to man. It was man, through that old I, who kept making God out to be an enemy.
God was in Christ reconciling the world to Himself, not imputing their trespasses to them.
2 Corinthians 5:19 (NKJV)
Maybe you say, but I feel guilty; I feel like God does not like me; I have done real evil. That may all be true of what you have done. But God is still not holding your sins against you, because He made Another, Jesus, pay for them in full. So now, when you choose to do good, it is not to dodge punishment or to earn a reward. It is simply because as He is, so are you now in this world. Good has become your nature, not your negotiation.
Do you know one of the biggest reasons we bear so little fruit, why we do not heal and bless as Jesus did? Because, unlike Jesus, we keep holding people's sins against them. You never once see Jesus do that. He offered the blessings of the Father to people no matter how rotten they were, because God has never been the angry deity we imagined. If God kept a record of wrongs, no one could stand. So He did not keep the record; He paid the debt Himself.
Ambassador and new creation
Two more truths finish the picture of who you are. You are an ambassador of Christ, His representative here on earth. An ambassador lives in a foreign land, but the laws that operate around him are the laws of the kingdom he represents, not the country he happens to stand in. The devil may be the god of this present world, but he cannot touch an ambassador. Instead, you carry the will and the wish of your King into this foreign place.
Therefore, if anyone is in Christ, he is a new creation; old things have passed away; behold, all things have become new.
2 Corinthians 5:17 (NKJV)
And you are a brand new creation, a kind of being that never existed before, one whom sin cannot contaminate, higher even than Adam. God took the sinless One and made Him to be sin for you, so that you could become the very righteousness of God. You cannot be more righteous today than you already are. By one sacrifice, He has perfected you forever.
Living from the inside out
Here, then, is the secret of unceasing fruitfulness. It is living from the inside out, knowing who you are in the spirit and partnering with God to bring that inward reality outward.
Do not be conformed to this world, but be transformed by the renewing of your mind.
Romans 12:2 (NKJV)
So stop thinking like the world. Stop staring at your natural. Let your mind be renewed as you take in the mercies of God, all He has done for you and in you, and then live from there. You are not an apple tree trying to make mangoes so that you can become a mango tree. You are a mango tree. Rest in who you already are, keep your eyes on the mirror of His word, and begin, without ceasing, to bear the fruit you already carry inside.