Let all that you do be done in love. (1 Corinthians 16:14)
There are at least two kinds of mystical experience of God: Ecstasy and Emphasis. Ecstasy is to take you out of yourself. The Greek word "ekstasis" literally means to stand ("stasis") outside ("ek") of oneself. Ecstasy is to experience self-transcendence, and often to have some kind of visionary experience that is utterly unlike everyday life. Perhaps a luminous Divine Darkness that envelops us, or a Divine Light which is infinitely brighter than our normal sight, or a vivid sense of the Personal Presence of God. In Ecstasy we experience rapturous personal union with God in Love on a separate plane of Reality than the normal and mundane plane of existence we are accustomed to. And that transcendent experience is often interpreted through symbols we know and understand, such as the "seeing" or "feeling" or "hearing" the personal presence of Jesus, or even his Mother Mary.
The other kind of mystical experience of God is Emphasis.