Ravi touches on some good points here, but the main point is that God reaches people in so many ways through other people; and where man does not reach, Jesus reveals Himself. Ultimately, man can only penetrate so far. It is only the Holy Spirit Himself who reaches each persons heart in the end.
As an Aside: Some of my pastors have personal testimonies where those who were having dreams actually found my pastor instead of the other way around. He and some friends had smuggled Bibles in China while it was still illegal. Their car broke down on a mountainside, leaving them to feel like God abandoned them. They soon realized that God had placed them there to be found. Some people who had been dreaming dreams of Jesus were told to meet the pastors there in their dreams. Soon-after they were found, the car started up again.