The mystic way refers to the stages in our journey into God. These are levels of oneness with God. They are rooted in the Bible, but explained by later Christian mystics.
For some people the traditional terminology (purgation, illumination, and union) is a stumbling block. Alternative language would be the beginner, the proficient, the advanced. Think of the child, the teen (young man), and the adult (father) (1 John 2:12-14).
1. Conversion
The Journey of a thousand miles begins with the first step. The first step on the Mystic path is conversion. This is the turning from a self-centered life to a God-centered life.
There are even stages in conversion. One begins as indifferent. The second phase is conviction. The final stage is repentance and belief, resulting in conversion.
2. Purgation
Most books on mysticism begin with this stage. This is the first part of sanctification, the separation from evil thoughts, words, and habits.
Most people struggle with this stage. For the tendencies of selfishness run deep. And it takes a lot of work to let go, surrender to God, and develop new habits of thoughts, words, and deeds.
3. Illumination
In this stage of the mystic way, one has to unlearn everything they learned before. They have to strip off the errors, the wrong ways of looking at things, the distorted perceptions.
Illumination is the process of trying to see things from God’s perspective. It is to think God’s thoughts after Him. It is a radical unknowing so that we may see things as they really are.
4. Union
Purgation is a oneness of our will with God’s will, illumination is a oneness of our mind with God’s mind, and union is a oneness of our being with God’s Being. In union, we become “participants of the divine nature” (2 Pet. 1:4).
Even in this stage there are levels. The first being the struggle to completely die to self. Here is the hardest part of union with God.
Before entering into full union with God most experience the dark night of the soul. Here everything is stripped away until there is nothing and nobody left. Only an empty vessel can receive the fullness of God.