I am married. Sometimes I like to be single because of life. This is, however, but for a moment in time.
I think it is ok to be single. But it has to be a good life - helping others in need, being cheerful, being honest, having a job with integrity, etc.
Perhaps you ask the question because you want to have a significant other but have not found the one and probably do not think you will find the one. Perhaps . . .this could be anything.
If you are to be living a single life, live a good one.