New believers, that's how.
The setting apart of the believer into ever increasing fruit and good works is a process.
If you were the rare believer that was born mature, I'm happy for you.
Even new believers can produce fruit. We don't need to become a mature believer before we finally produce any fruit at all. As we grow to maturity in Christ, there will be ever increasing fruit, but that does not mean we remain fruitless until then. Right out of the starting gate as a new believer, I was sharing the gospel with everyone I knew and within 3-4 months, my wife, my son, my brother in law and sister in law all received Christ through faith. Praise the Lord!
But don't project your experience onto others.
I never said that I was born mature. Going from babes in Christ to maturity in Christ is a process and doesn't happen overnight.
IMO, 95% of genuinely believing, saved Christians are type 2 & 3 soil believers.
So 95% of genuine believing, saved Christians produce no fruit at all?

So according to your estimate, what % of saved Christians do YOU believe end up losing their salvation? 75%? 50%? 25%?
The saved Galatians were type 2 soil believers. They believed for a while, and arguably with joy, but fell away.
In a different post, you said we will have to wait to see if these Galatians permanently fell away, but now you confidently argue they fell away and lost their salvation? Sometimes I think you just make stuff up as you go along in order to accommodate your biased theology.
If you do not grow up to good works in your faith and instead persist in dead faith (faith with no works to show for it) that faith will not save you. In the end you will be rejected when Christ returns.
Persist in dead faith? Believers have a living faith (Ephesians 2:5-10) which results in producing good works. All genuine believers are fruitful, but not all are equally fruitful. In James 2:14, we read of one who
says/claims he has faith but has
no works (to validate his claim). That is not genuine faith, but a
bare profession of faith. So when James asks, "Can
that faith save him?" he is saying nothing against genuine faith, but only against an
empty profession of faith/dead faith. *So James does not teach that we are saved "by" works or that dead faith is authentic faith. His concern is to
show the reality of the faith professed by the individual (James 2:18) and demonstrate that the faith claimed (James 2:14) by the individual is genuine. Simple!
Faith without works can not save. James says so. If you do not grow up into works of righteousness, you have a faith that can not save you. Does God expect you to be mature on the day you were born again? Of course not. Can you stay that way to the very end? No, of course not.
I know that faith without works (empty profession of faith/dead faith that results in producing no works at all) cannot save. Of course God does not expect us to be mature on the day we were born again, but he also doesn't expect us to finally start producing good works after we become mature in Christ either. It doesn't take a mature believer to share the gospel, show love towards others, clothe and feed the poor etc.. I've seen many new believers exhibit this fruit in their lives.
The mistake you are making is saying all failed believing without exception was never real to begin with.
Well then show me the words in the Bible to make your argument conclusive -- "lost salvation." God's saints are
preserved forever.. (Psalm 37:28) Jesus
gives His sheep eternal life, they shall never perish or be snatched from His hand.. (John 10:27-28) Those whom God
justified, He also glorified. (Romans 8:30) Those who believe the gospel are
sealed with the Holy Spirit of promise until the redemption of the purchased possession. (Ephesians 1:3-14) He who has
begun a good work in us (believers)
will complete it until the day of Jesus Christ. (Philippians 1:6) If your theory about failed believing/losing salvation was correct, then all of these promises are out the window.
No, the parable of the sower shows us it can be a matter of weak vs. strong faith, not just fake vs. real faith. Until you can grasp that there are, both, fake temporary 'believers' and real temporary believers you will continue to beat your osas drum.
There are no real "temporary" believers, but there are numerous "temporary" make believers. Saving belief in Christ continues and is not some shallow, temporary belief that has no root, produces no fruit and withers away. Until you finally get that through your head, you will continue to beat your nosas drum.