evil in the world

You sound like you really want to know.
The only one able to really let you know is the Sovereign Elohim.
If He doesn't, no way.
If He does, it is accomplished.
email if permitted.

what would it take for you to believe? I mean really believe, no doubt, no second guessing?

Let's look at what The Bible says...(And when he is come, (talking about The Holy Spirit) he will reprove the world of sin, and of righteousness, and of judgement: Of sin, because they believe not on me:...." -John 16:8-9

So if you can see that the world is definitely evil (which is most certainly is) then would you say that you yourself are a sinner, too?

The Word of God says in Romans 3:10 that "There is none righteous, no, not one:"

"For all have sinned and come short of the glory of God": - Romans 3:33

"Wherefore as by one man sin entered into the world, and death by sin; and so death passed upon all men; for that all have sinned:" - Romans 5:12

"But God commandeth his love toward us, in that, while we were yet sinners, Christ died for us." -Romans 5:8

"That if thou shalt confess with thy mouth the Lord Jesus, and shalt believe in thine heart that God hath raised him from the dead thou shalt be saved.
For with the heart man believeth unto righteousness; and with the mouth confession is made unto salvation.
For the scripture saith, Whosoever believeth on him shall not be ashamed. For there is no difference between the Jew and the Greek:for the same Lord over all is rich unto all that call upon. For whosoever shall call on the name of the Lord shall be saved." -Romans 10:9-13

So the question is, what are you going to do? God is only a thought away.

god(s) of this world might be a thought away, and not even alive,
but
the Author of Life, Creator of All, Who Breathed Scripture through men of His choosing,
is much closer than a thought...
However, it takes obedient faith, not thought to please Yhvh - to avoid the common deception that thinking about what is good makes the thinker good somehow: no, thinking does not bring a soul to Healing.
..
There is Healing (Salvation) in only one name, that is Yahshua, Jesus, the Messiah, the Master, the Lamb Who was Slain and is Risen.
when He, Yahshua, is come, He is holy, and spirit.... note that holy is always an adjective in all of the original languages of Scripture - holy is never a name nor part of a name in any Scripture in Hebrew, Aramaic nor Greek. (translators took liberties to pick and choose where they would capitalize an adjective to make it look like a name in english for example, but holy remains an adjective in every case it is found in Scripture.)

You're right. We're not saved by intellectually acknowledging Jesus as Savior and God. We have to come to a saving knowledge of what is called faith and accept the free gift of salvation He offers in order to inherit the kingdom of heaven.

Just read about Nicodemus in The Bible. (John 3:1-21)