A mystic is in love with God.
That is in whichever sense of Deity may be appropriate to him or her.
It is not merely an instinct or an emotional response. It is an infinite love.
Love is not purely emotional, it is abstract and transcendent and lasting; emotions come and go and instinct flickers.
But God is at the bottom, inside of us, underneath our being in the world, and therefore incredibly deep, without comparison or compromise.