What is your true reason for unbelief? Possible long answer to the question confirmed by the two verses below: You really love your current lifestyle and refuse to change. You do not want to be held accountable for your lifestyle and choices by anyone, including God.
John 3:19 And this is the condemnation, that light is come into the world, and men loved darkness rather than light, because their deeds were evil.
John 3:20 For every one that doeth evil hateth the light, neither cometh to the light, lest his deeds should be reproved.
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.
[Many get help from Satan and his spirit in unbelief; sadly they don't realize it. The god of this world, has blinded the minds of those who do not believe. See John 12:31, 40 and Ephesians 2:1-3].
2 Thessalonians 2:11 And for this cause God shall send them strong delusion, that they should believe a lie:
2 Thessalonians 2:12 That they all might be damned who believed not the truth, but had pleasure in unrighteousness.
[If you want to believe lies, God will send you strong delusion to believe those lies. Who is the father of lies? See John 8:44 for your answer. God will close your eyes to the truth; He makes it easy for you to be deceived. See Isaiah 29:10. Look at how people are so comfortable with enjoying their sins. But, one thing to remember is, God is on the throne and has always been in control. He has allowed Satan to perform his evil deeds on those that choose not to believe. Is it part of Gods' plan? I believe it is. God has a reason for everything He does. Certainly a lot to contemplate and pray about].
* There is hope, even for the most adamant unbelievers. See John 3:16 and 2 Peter 3:9!