Because it irritates their demons and convicts them in their heart that their behavior is evil. And this makes them feel uncomfortable and stressed out and they don’t want to feel uncomfortable and stressed out for doing wrong. Many of them would rather you lie to them than tell them the truth because when you lie they can continue in their sin comfortable and unbothered.

So they would rather you keep God’s truths to yourself so they can continue in their evil delusion searing their consciences by lying to themselves, falsely convincing themselves, that nothing is wrong with their behavior.

So they can continue to operate in their evil ways, happily and comfortably, without any stress or worry, with a seared conscience. But unfortunately, that mindset eventually leads to death both spiritually and physically. And running from the truth doesn’t set you free from fear and anxiety because when you see these things begin to unfold it will produce fear and anxiety. But following/obeying the truth does set you free from fear and anxiety.

Psalm 121:7-8 (New International Version)
The Lord will keep you from all harm— he will watch over your life; the Lord will watch over your coming and going both now and forevermore.

Proverbs 1:24-33

²² How long, ye simple ones, will ye love simplicity? and the scorners delight in their scorning, and fools hate knowledge?

²³ Turn you at my reproof: behold, I will pour out my spirit unto you, I will make known my words unto you.

²⁴ Because I have called, and ye refused; I have stretched out my hand, and no man regarded;

²⁵ But ye have set at nought all my counsel, and would none of my reproof:

²⁶ I also will laugh at your calamity; I will mock when your fear cometh;

²⁷ When your fear cometh as desolation, and your destruction cometh as a whirlwind; when distress and anguish cometh upon you.

²⁸ Then shall they call upon me, but I will not answer; they shall seek me early, but they shall not find me:

²⁹ For that they hated knowledge, and did not choose the fear of the Lord:

³⁰ They would none of my counsel: they despised all my reproof.

³¹ Therefore shall they eat of the fruit of their own way, and be filled with their own devices.

³² For the turning away of the simple shall slay them, and the prosperity of fools shall destroy them.

³³ But whoso hearkeneth unto me shall dwell safely, and shall be quiet from fear of evil.

Proverbs 3:24-26

²⁴ When thou liest down, thou shalt not be afraid: yea, thou shalt lie down, and thy sleep shall be sweet.

²⁵ Be not afraid of sudden fear, neither of the desolation of the wicked, when it cometh.

²⁶ For the Lord shall be thy confidence, and shall keep thy foot from being taken.

1 Timothy 4:1-2 King James Version

4 Now the Spirit speaketh expressly, that in the latter times some shall depart from the faith, giving heed to seducing spirits, and doctrines of devils;

² Speaking lies in hypocrisy; having their conscience seared with a hot iron