A friend and enemy are two sides of the same Coin. Coin resembles you. A friend knows your in and out and is with you during your trying times wheras an enemy once becomes an enemy will keep a safe distance with you. In turn you too won't let it get disclose any of your secrets to him/her. When it comes to your friend, you just keep your heart open and reveals that secretWhich you hide from your kith and keen. A friend is the person who knows you better than yourself. A minute misunderstanding can lead to a disaster if not handled with care. Friendship requires commitment and assurance, you break it the thread of your love is mended with a knot which won't keep it for long.
Hence, it's wisely said,
" A friend can betray you, but an enemy will always stay the same."