Why God should want and need us is a mystery. But it is true: otherwise he would not have created us and life would ultimately have no meaning for us. It is good to remember that in God the is a constancy, a consistency of attitude which never changes, irrespective of what we are or how we act: he never changes in is wanting us or needing us.
Soon after you're dead - we're not sure how long - but not long, you'll be united with the most ecstatic love you've ever known. As one of the best things in your life was human love, this will be love, but much more satisfying, and it will last forever.