Logic cannot comprehend love; so much the worse for logic.
Science studies the repeatable; history studies the unrepeatable.
Time matters; it was part of the original good creation. Though it may well itself be transformed in ways we cannot at present even begin to imagine, we should not allow ourselves to be seduced by the language of eternity (as in the phrase 'eternal life,' which in the New Testament regularly refers not to a nontemporal future existence but to 'the life of the coming age') into imagining, as one old song puts it, that 'time shall be no more.' No: 'the old field of space, time, matter and the senses is to be weeded, dug, and sown for a new crop. We may be tired of that old field: God is not.
Unless a person can give reasons, there is, literally, no reason why anyone else should take that person seriously. But without reasons, all we are left with is emotional blackmail. We sometimes call it 'moral blackmail,' but it has nothing to do with morals, only with the implied juvenile threat of having a tantrum unless everyone else gives in.
What you do in the Lord is not in vain. You are not oiling the wheels of a machine that's about to roll over a cliff. You are not restoring a great painting that's shortly going to be thrown on the fire. You are not planting rosed in a garden that's about to be dug up for a building site. You are -- strange though it may seem, almost as hard to believe as the resurrection itself -- accomplishing something that will become in due course part of God's new world. Every act of love, gratitude, and kindness; every work of art or music inspired by the love of God and delight in the beauty of his creation; every minute spent teaching a severely handicapped child to read or walk; every act of care and nurture, of comfort and support, for one's fellow human beings and for that matter one's fellow nonhuman creatures; and of course every prayer, all Spirit-led teaching, every deed that spreads the gospel, builds up the church, embraces and embodies holiness rather than corruption, and make the name of Jesus honored in the world -- all of this will find its way, through the resurrecting power of God, into the new creation that God will one day make.
What we have at the moment isn't as the old liturgies used to say, 'the sure and certain hope of the resurrection of the dead,' but a vague and fuzzy optimism that somehow things may work out in the end.