Everyone needs friends of either sex. Friends enjoy their companionship, comradeship and adventures, but the essential quality of friendship is an unswerving commitment to the good of another. You can rely on a friend when it counts.
Immature love is often skewed towards sensual and sexual values, or it is almost solely based on the pull of emotions and sensations. If you allow these emotions to dictate the progress of your relationship then you will not have the opportunity to first of all be friends.
It is in the experiences of friendship that emotional and sensual reactions take a back seat and the real person comes to the fore. "Being cool" with a friend will always be seen as a sham. Friendship is the proving ground for a relationship that is going to last.
Friendships between male and female that do not progress to married love are a great good in themselves. In some cases their very existence may have avoided heartbreak for people who would have entered a sexually intimate relationship which was destined for failure.