Ever encounter the question "if you don't apply the word eternal to torment how can you apply it to life?"?
I was called in recently and grilled by the associate pastor of the church I attend because I shared UR in a home group - didn't plan on it, just happened. My pastor was specifically asking about Matthew 25 and he said "how can you say that eternal means "of or for an age" when it applies to destruction but means "eternal" when applied to life in the same passage". He had alread emphasized his belief that Christ came to conquer sin, death and Satan so with his permission I answered him with a simple question as my answer "If there is no death because it has been conquered then how long does life last?" He was honest enough to answer "forever" and it seemed to answer the question he had because we moved on from there.
I know there are way more in depth answers to the question, but I like this one because it is so simple.