Caught as we are in the limitations of the here and now, eternal life is only a small foretaste, but it is the real thing. Eternal life is now. The most significant joy of eternal life is love. Love, love and more love. As does also the first Letter of John.
Love is the litmus test.
Love of God, love of each other. I have no doubt that love is a far more important ingredient of eternal life than is the fact of surviving death. The promise of our Christ does not end there. He assures us that none of his flock will perish. They shall never perish.