What is fruit?
James tells us there will be works. When I was growing up I thought works or fruit in a Christian's life was how many people I brought to God. I am not really sure where that thinking came from. It was definitely the focal point of churches, Christian events and missionary success.
However, salvation is in the hand of God. We cannot make anyone believe. So, it is wrong to use that as a sign of fruit.
I think God does give us a very clear picture of fruit. I think it would be describe better as change. We change as a believer. That change becomes evident to others and affects how we interact in the world.
There are too many verses that support this to be able to list more than a small fraction of them. Just read the whole New Testament. Well and the Old Testament :) also supports this idea of change, Ezekiel 11 so beautifully tells us that God does this work. "Then I will give them one heart, and I will put a new spirit within them, [fn] and take the stony heart out of their flesh, and give them a heart of flesh,that they may walk in My statutes and keep My judgments and do them; and they shall be My people, and I will be their God."
Titus 3 says, "For we also once were foolish ourselves, disobedient, deceived, enslaved to various lusts and pleasures, spending our life in malice and envy, hateful, hating one another.But when the kindness of God our Savior and His love for mankind appeared, He saved us, not on the basis of deeds which we have done in righteousness, but according to His mercy, by the washing of regeneration and renewing by the Holy Spirit,"
He saved us from what? From being foolish, disobedient, deceived, enslaved to various lusts and pleasures, spending our life in malice and envy, hateful, hating one another. We were ONCE that way.
2 Peter 1:"Now for this very reason also, applying all diligence, in your faith supply moral [fn]excellence, and in yourmoral excellence, knowledge,and in your knowledge, self-control, and in your self-control, perseverance, and in your perseverance, godliness,and in your godliness, brotherly kindness, and in yourbrotherly kindness, love.For if these qualities are yours and are increasing, they render you neither useless nor unfruitful in the true knowledge of our Lord Jesus Christ.For he who lacks these qualities is blind or short-sighted, having forgotten his purification from his former sins.Therefore, brethren, be all the more diligent to make certain about His calling and choosing you; for as long as you practice these things, you will never stumble;" (underline my emphasis)
Galatians 5 tells us what the fruit of the Spirit is and gives a clear difference between walking in the flesh and Spirit. But I say, walk by the Spirit, and you will not carry out the desire of the flesh.17 For the flesh sets its desire against the Spirit, and the Spirit against the flesh; for these are in opposition to one another, so that you may not do the things that you please. 18 But if you are led by the Spirit, you are not under the Law.19 Now the deeds of the flesh are evident, which are: immorality, impurity, sensuality, 20 idolatry, sorcery, enmities, strife, jealousy, outbursts of anger, disputes, dissensions,factions, 21 envying, drunkenness, carousing, and things like these, of which I forewarn you, just as I have forewarned you, that those who practice such things will not inherit the kingdom of God. 22 But the fruit of the Spirit is love, joy, peace, patience, kindness, goodness, faithfulness, 23 gentleness, self-control; against such things there is no law. 24 Now those who belong to Christ Jesus have crucified the flesh with its passions and desires.
You see there is a battle going on. In that battle the Spirit is stronger and God will complete His work. God will bring change for His glory! We are saved from our previous life, death controlled by the flesh. What power is it of God to save us from hell but not the flesh that binds us. None at all! Salvation is done, salvation is being done and salvation will be completed. The same grace that freed us from hell is working within us to free us from our flesh. Change! God is powerful. I love Paul Washer's story: (paraphrased) If I stand before you tonight and tell you that I was hit by an 18 wheeler before coming here tonight, you would claim I am crazy or a liar. You know that if a truck ran over me, I would definitely look different. I would not be standing here. Isn't God bigger than a truck?
1 John tells us many things about a believer and non-believer. I would recommend meditating on the whole book. A believer will love God's laws, will walk in the light, will love his brother, will keep His commandments, will not love this world or the lusts of this world and abides in Him.
Could a person not show ANY fruit and be saved? I don't think scripture supports that, but I would not be one to judge it. Scripture calls for God's judgment on those who don't. (1 Corinthians 11:30-32) However, I would strongly advise that person to do what scripture commands: EXAMINE YOURSELF.