Difference between "everlasting" and "eternal"
Solution 1:
I've consulted several different dictionaries, and all say pretty much that both words mean the same thing. At first, I thought that "eternal" may indicate no start or end, while "everlasting" only specifies no end. But that is NOT the case. My Random House Websters College Dictionary (2001) lists "eternal" as a synonym for everlasting. The American Heritage Dictionary of the English Language 3rd edition (1992) lists "everlasting" as a synonym for eternal. My Merriam-Webster's Collegiate Dictionary 10th Edition (1996) lists each word as a synonym for the other.
Having said that, this response is admittedly subjective. I think the main difference is in connotation. Part of that connotation is endpoint. Eternal seems to emphasize no start or end, while everlasting emphasizes the lack of ending. Also, in my mind, "eternal" has a sense of stillness and lack of change. While "everlasting" has a more dynamic and vibrant feel.
Solution 2:
Just a snippet from Difference Between Eternal and Everlasting
Summary:
According to the English language, “eternal” means “without beginning or end, always existing, lasting forever”; whereas “everlasting” means “lasting forever, lasting for a very long time, for an indefinitely long time.”
Theologically, “eternal” means “not within any time limit, outside of time and existing without a beginning or end, like spirit”; whereas “everlasting” means “the life which did not always exist but was granted to God and it was forever, running within time, or something similar, which has a beginning but no end.”
See the original article for more information.