When you tell God, "I want the truth more than anything else," he will reveal his truth to you in a variety of ways, such as through creation or your conscience and also through careful consideration.
In other words, truth is knowable. You can test it; you can experiment with it; you can prove it.
If I want to go to San Francisco and I follow a map that takes me to San Francisco, and the next week I follow the same map to San Francisco again, eventually I figure out that the map is true.
The same is true of the Bible: If you follow its map again and again, you'll find it to be true. It always takes you where it says it's going to take you. You may not always like where it takes you, but it always takes you where it says it's going to take you.
Often people say, "Why won't God just write it in the sky?" Why would God do that? He gave you a brain. But most people never slow down long enough for such careful consideration. Most people just drift through life.
The Bible tells us, "Carefully consider the path for your feet, and all your ways will be established." (Proverbs 4:26, HCSB)
Spend some time in careful consideration, in thoughtful observation, and ask yourself: "Am I on a true path?"