Sex is one of the most wonderful acts of a human being where they share their love and themselves with another whom they love.
However, there is a time and place for sex, and the best time and place is in a committed relationship which has security, permanence and endurance.
Having sex for the sake of sex is simply engaging in selfish pleasure. Sex makes life, so take care that the life you make is a life you would want to live yourself.
However sex can be bad too, if you do not use contraception, it can lead to unwanted pregnancy, and STD's, and STI's.