It isn't a matter of not believing in him, it is a matter of your sincerely wanting to know the true God that decides whether or not God lets people get to know him. There are two primarily involved in salvation, and YOU are one of them.
{Also, the common religious view of hell is incompatible with the Bible, as the source box below can reveal.)
God makes himself available to every human, in fact, Jesus said He is looking for people who want to worship him. In fact, God sent his Son Jesus to provide the way to approach Him.
John 4:23: Nevertheless, the hour is coming, and it is now, when the true worshippers will worship the Father with spirit and truth, for indeed, the Father is looking for ones like these to worship him.
But WE have to make that step toward God, to seek him honestly and regularly, and then he will let us find him.
1 Chronicles 28:9: “If you search for him, he will let himself be found by you.”
He is not looking for people to condemn, He is looking for people to save from death due to sin. You may be familiar with John 3:16, but verse 17 clearly establishes this truth.
John 3:17: For God did not send his Son into the world for him to judge the world, but for the world to be saved through him.
1 Chronicles 16:9: "For the eyes of Jehovah are roving about through all the earth to show his strength in behalf of those whose heart is complete toward him."
Neither does He hide himself from those who really want to know him, in fact he is always there to make himself known to them.
Acts 17:26-27: And he made out of one man every nation of men, to dwell upon the entire surface of the earth, and he decreed the appointed seasons and the set limits of the dwelling of men, for them to seek God, if they might grope for him and really find him, although, in fact, he is not far off from each one of us.
This is why those so-called "prayer experiments" that some scientifically minded people try to make God show Himself by doing something that they want Him to do, won't ever work. He knows what the heart, or real motivating inclination, of each human is, and He will not put on an act for us, like faithless Herod wanted for Jesus to perform some sign for him. Luke 23:8-9
But he will make Himself known for those who want to know him, because He knows that it means everlasting life for them to come to know Him.
John 17:3 This means everlasting life, their coming to know you, the only true God, and the one whom you sent, Jesus Christ.
And His love for us is what motivates the true God to seek them out, and also to ignore those who are insincere:
1 Peter 3:12 For the eyes of Jehovah are on the righteous, and his ears listen to their supplication, but the face of Jehovah is against those doing bad things.”