Just as, it is impossible for the ocean to fit into a glass, it is impossible for limited human mind to comprehend eternity. Nevertheless, even though he does not understand eternity, he can know that it exists. Understanding one thing, while believing and knowing another.
Humankind is limited in all aspects. There is a beginning of his life. As every beginning has an end, this life will end too. As you see, man can only perform limited works in his short life, which has a beginning and an end. His eyes can detect 2.5% of the all-existing beams. His ears can hear certain frequencies.
Your vote on this answer has already been received
It is not fully comprehensible but to a great extent one can reach the edge of it by acquiring Samadhi. I would like to suggest a book named SADHU PRASANG EVAM SATSANG WRITTEN BY PT. GOPINATH KAVIRAJ in which there is the true story of one Jyoti ji who could go anywhere in the universe in his minute form.. ... the intricacies of eternity are so amazing ... is worth knowing through the experiences narrated in the story.....