Here in the practical West, this has not been a popular career goal. We presume that the real accomplishments of the world are won by hardworking, hardheaded people. "Mystical" seems just about the opposite of this, swoony and contrary to common sense, if not to reality. We picture a mystic as someone wispy, inscrutable, and frankly, kinda stoned.
It's a false impression. The saints who came nearest to divine union while on earth showed a remarkable range of personalities. St. Paul himself was practical, hardy, brave, and an expert debater, not a floaty dreamer. Yet he said that he knew somebody (himself) who had been caught up "to the third heaven," insensible of his own body, and hearing things that cannot be spoken (2 Corinthians 12:2).
Furthermore, even those who had overwhelming spiritual experiences while on earth remained earthy people, still prone to temptation and sin. None reached perfection in this life. As one desert monk said when asked how such monks spent their time, "We fall and we get up, we fall and we get up."
In fact, many who undertake the serious journey toward union never experience any thrills or chills. They find it a gradual process that they cooperate with as best they can, moving gradually into greater peace and greater capacity to love. Decades later, they will still not be perfect, and might not even be as outwardly good as an unbelieving neighbor. But they're better than they otherwise would have been.
In fact, they would advise that any spine-tingling experiences be held at arm's length and critically evaluated . The way to Christ is marked by perseverance and surrender, not giddy flapping around.
Even for Paul, the end was not taken for granted. "I do not consider that I have made it my own...but I press on toward the goal for the prize of the upward call of God in Christ Jesus" (Philippians 3:13-14). He used the analogy of an athlete training for a race, and Christians ever afterward have applied the same metaphor.
Like a physical athlete, a spiritual athlete can benefit from the advice of predecessors. Books about how to cultivate constant prayer and dwell in Jesus' presence have been produced continually since the church's earliest years. Some consistent rules emerge:
1. This path is for everybody, not just the holy few. There is no other point to the Christian life besides transforming union with Christ. Get on with it.
2. Our bodies matter, and physical disciplines (like fasting, chastity, and sacrificial giving) exercise spiritual muscles. If you don't keep those disciplines, you're not "bad"--you just miss the benefit of growth, like a weightlifter who skimps on his repetitions.
3. You can't do it alone. There is serious danger of falling prey to delusion, since spiritual forces of evil "prowl about like a roaring lion" (I Peter 5:8). "The Kingdom of God is within you" (Luke 17:21), but that's not the only thing within you; you need a spiritual director to act as a "personal trainer," to provide accountability and discernment and tell you what you sometimes don't want to hear.
4. You also need to be part of a local community because other people are the best sandpaper for your rough edges. Though injustice must sometimes be addressed, never judge or criticize other individuals; their situation is between them and God. Put them first, love even your enemies, and practice humility, which vanquishes every evil.
5. You also need to be in an ancient, global community, so that the wisdom guiding you will have deep and broad roots. If people don't question their culture's authority, they unconsciously absorb its worldview. This distorts some truths and conceals others. What is found consistent among believers over the millennia has been stonewashed, cleansed of cultural detritus.
6. Finally, most difficult, you have to repent. Up till now, mystical union with Christ might have sounded like something dignified and magnificent, something you intrinsically deserve. But Jesus came only to save sinners. He's looking for the humble souls who are ready to see how much they've been forgiven.
Thus, when the ancient church developed a short prayer for constant repetition, to fulfill Paul's exhortation to "Pray constantly" (I Thessalonians 5:17), they didn't choose a prayer that dwelt on God's glory or our own value. The prayer is, "Lord Jesus Christ, Son of God, have mercy on me, a sinner." It is in this place of humility and self-abandonment that transformation begins.
And what comes after that? I don't know. I'm a crummy athlete; every once in a while I go a block or so, but I keep stopping for ice cream. Perhaps you will be one of those spiritual athletes who gets far down the path and sends postcards back, and adds to the communal wisdom. I hope so. And pray for me, a sinner.