My dear Friend, When I say John is my friend, it doesn't mean that I created John it jus means that i m associating myself with John. Also note that John's Existence doesn't depend on your calling him as your friend. John still exist, even if u don't call him friend. And as far as Lord Krishna is concern, we never say Krishna is mine, we say Krishna is Ours(as acknowledged by U) and ours include everyone, i.e, If i m talking to u and tell u OUR GOD Krisha,than u r also included in OUR, same as when we say John is OUR Friend.