Hi there,
Mysticism and Occultism are related but are also distinct.
Mysticism is a religion that brings a believer into contact with the ultimate reality, ie. God.
Occultism is the study of the paranormal which can or cannot be related to God or the ultimate reality.
At least this is my way of distinguishing the two.

Louiza

I used this definition of a mystic in a class I organized a few years ago.

Mystic/mysticism - definition Mystic: one initiated, one professing to undergo profound spiritual experience, visionary, spiritual, supernatural, transcendental, one overwhelmingly driven to follow the sacred.
Mysticism is the doctrine that knowledge of spiritual truths can be acquired by intuition and meditation.
Mysticism lies at the very depth of spiritual consciousness; it has an intensity, power, and energy, matched by nothing else.

Characteristic experiences:
1. Mystics experience to an extraordinary degree the profoundly personal encounter with the energy of divine life.
2. Mystics often perceive the presence of God throughout the world of nature and in all that is alive, leading to a transfiguration of the ordinary all around them.
3. Mystics experience an inner and an outer quest, a journey that leads deeply into the divine center of one's own soul but then moves outward again to the concerns of the created world and the world of suffering.
4. Mystics travel along the margins of the ordinary and the extraordinary, the world of the mundane, and the world of the spirit where all things are made whole.
5. Mystics seek participation in divine life, union, and communion with God.
6. Mystics experience a desire that is kindled by the fire of divine love itself, this moves the mystic in their search and leads them on arduous journeys, to discover and proclaim the all-encompassing love of God for all human kind.
7. Mystics quest for loving union and communion with God; this quest runs like a golden thread through life and the centuries.
8. Mystics experience God in a dazzling darkness brighter than the brightest light.
9. Mystics experience a splendor and empowerment that they ceaselessly describe, even when affirming that it is entirely incommunicable.
10. Mystics represents the great company of such seers who want to pass on to others the precious riches bestowed upon them.
11. Mystics experience the sacred as the ultimate Godhead, or Ground of Being - God the Father and God the Mother - God intimately present.
12. Mystics may be passive mystics who reject the world and withdraw from it
13. Mystics may be active mystics who are led back into the world and become immersed in a round of activities, profoundly transformed by a new spirit.
14. Mystics communicate the inspiring heritage of a great mystery and an all consuming love, sometimes verbally and sometimes through silence, but always through the way they live their life..
15. Mystics experience a profound spiritual integration with the promise of joy and passion, ecstasy, and suffering overcome.
16. Mystics experience a spiritual wholeness and completion that reaches its goal in God.
Mystics struggle to find some kind of balance between the world they know as ordinary and that can become transcendent and the world of divinity where they can live fully in their spirit.