Correct...reading stories of tribal individuals who desired to know who the God is is more than interesting. Some got lost in the jungle only to come out into a Missionary camp where they did indeed learn of Christ. Their stories are compelling. At the heart of this was their steadfast and deep yearning to know if there was indeed a God they truly wanted to know Him.......and He did not disappoint them.
There are also accounts of people who have had visions and/or visitations, by angels or Christ, telling them of this.
2 Peter 3:9
The Lord is not slow to fulfill his promise as some count slowness, but is patient toward you, not wishing that any should perish, but that all should reach repentance.
Ezekiel 33:11
Say to them, As I live, declares the Lord GOD, I have no pleasure in the death of the wicked, but that the wicked turn from his way and live; turn back, turn back from your evil ways, for why will you die, O house of Israel?