Good questions
If everyone begins their journey as an unbeliever and without the Holy Spirit, as surely they must, and God really does want to save as many as possible, then why is the Bible written specifically so that only believers and those who already have the Holy Spirit can understand it?
Though one might have been an unbeliever, and in his/her heart God sees good things, God calls him forth.
Proverbs 1:24 Because I have called, and ye refused; I have stretched out my hand, and no man regarded;
The Wisdom of God is calling because His Father's will is to save all men.
I Timothy 2:4
Who will have all men to be saved,
and to come unto the knowledge of the truth.
There are people who read the Bible only to be against God's declarations. And some of them are even thankful to the words of the adversary of God.
Is not this intentionally preventing the very ones who need it the most from ever understanding it? Is not that the reason why Jesus even spoke to the people in parables; to prevent them from understanding and to prevent them from being saved? That is what the Bible teaches is it not?
The above were merely your self-interpretation.
Proverbs 2:6 For the LORD giveth wisdom: out of his mouth cometh knowledge and understanding.
2 Corinthians 4:4 In whom the god of this world hath blinded the minds of them which believe not, lest the light of the glorious gospel of Christ, who is the image of God, should shine unto them.
Of course in addition to this, the problem still remains that even Holy Spirit led and filled believers cannot agree on very basic and critical doctrines of the faith or even how to interpret the Bible.
Thanks.
Those believers cannot agree? Why? Let the Bible speak:
Philippians 3:2 says "Beware of dogs, beware of evil workers, beware of the concision."
Who are these dogs?
Isaiah 56:11 says
"Yea, they are greedy dogs which can never have enough,
and they are shepherds that cannot understand: they all look to their own way, every one for his gain, from his quarter.
As simple as that, besides,
Philippians 1:15 Some indeed preach Christ even of envy and strife; and some also of good will:
Of course, some discussed in opposition to Apostolic doctrines because of envy and strife, meaning, others envy the assembly of the saints and they want them to involve in strife. And these "some" who preach Christ of good will are none other than the brethren which are yet in the world.
1 Peter 5:9 Whom resist stedfast in the faith, knowing that the same afflictions are accomplished in your brethren that are in the world.