The guy doesn't want to be friends or lovers with you anymore. It's over. Don't hassle him. Move on.

rekindle a fire = to make a fire that has died down bright again The image is clear now.

To rekindle means to revive, renew, to arouse again. It is often used with reference to hopes or feelings which have been lost or diminished. So to 'rekindle a friendship or more' means to revive feelings of friendship or love. But if you have remained friends then you can't rekindle friendship. I think this guy only wants to be casual friends as he's afraid spending a lot of time together will lead to you wanting to be more than just friends (=have a relationship). His reason for not wanting to have a relationship is that you have different lives. Without knowing what your lives are like it's difficult to understand how they are different. But whatever his reasons are, it's probably better to forget him. There is no point in wanting to be with someone who doesn't want to be with you!