The Guiding Tree was at the center of The Great Forest in the Talaxian afterlife. The Talaxians believed that the deceased met a close family member at the Guiding Tree and were then lead to a reunion with his or her ancestors.
When Neelix temporally died in 2374, he didn't see the Guiding Tree and questioned his faith. He later imagined it in a horrific hallucination. Naomi Wildman later had a dream of the forest where she sat under the guiding tree. (VOY: "Mortal Coil")