That is a difficult question and I honestly cannot give you an answer that is based from my own experience. But, God willing, I will give you something that will help out at least a little bit.
First of all, contemplation (as I have come to understand it in Orthodoxy) has nothing to do with the imagination. So, we do not picture Christ in our minds in order to contemplate Him and His face. Doing so ultimately leads to idolatry because we begin to feel the stirrings in our imagination are divine and we can end up worshiping this image that we have conjured. God speaks to us through our heart and through the nous, which is the spiritual eye of the soul. As St. Gregory of Nyssa said, Concepts create idols, only wonder understands anything. Thousands of years of experience in prayerful guidance with the Holy Spirit has shown us that the imagination is a dangerous place to dwell during prayer.
Secondly, contemplation is participation. True contemplation of Christ our God is not something that is possible without participating in the divine energies of Christ Himself. We cannot intimately know Christ intellectually, only through union and communion with Him.
Those Who Beheld God
There are a handful of biblical examples that come to mind of those who have contemplated the face of Christ:
- Moses, who upon seeing Christ, literally glowed as even his body participated to some degree with the energies of Christ on Mt. Sinai.
- The holy martyr Stephen (in Acts 7) whose face glowed like an angel as, through the Holy Spirit, his illuminated nous beheld Christ and shared in His glory.
- The disciples on Mt. Tabor were given a glimpse of Christ’s divinity when He was transfigured before them. Christ did not change, but he opened the eye of the soul, their nous, in order that they could contemplate Him as He really is — at least to the extent to which they were capable. The whole experience caused the disciples to fall upon their faces in fear.
There are also the examples of the Apostle John in the book of Revelations, the prophets Daniel and Isaiah, and a multitude of saints in the Church. There is one common theme in most of the accounts: all of them felt unworthy to behold such a divine vision. In this way we can discern what is from God and what is from the devil, or simply from our imagination. The former produces contrition and humility; the latter two tend to puff a person up.
Contemplation and Salvation
We were all made to contemplate the face of Christ, and we do so through the path of salvation, which generally happens in three stages. Try not to think of these “stages” in an abrupt way. I believe one will frequently overlap with another. For example, a person may be progressing along the path of purification while also having moments of illumination.
The first stage, purification, is where we spend most of our lives in these carnal and sinful times that we live in. In this stage, we receive the grace of Christ to struggle with and overcome the passions that have ensnared us our whole lives. Often, we discover that some form of pride is the chief passion with which we must wrestle.
Purification cleanses the nous not only so that one may see God, but also participate in Him. At the Second Coming of Christ, all will see God and experience Him, but only those working toward purification will participate in Him.
Going back to the example of Moses when he came down from Mt. Sinai, we see that he was aglow with the divine grace of God. However, the people of Israel could not bear to look at him. Why, if he was simply bearing the grace of God? The answer is that God’s grace and love are ultimately experienced as fire, which has both illuminating and caustic properties. For those who are pursuing the path of purification, they will experience God’s fiery grace as light while those who justified their sins and did not repent will see God, but God’s presence will be caustic. This is not a torture that God implements, but a reflection of the state of each soul.
The soul pursuing purification is gifted with discernment, which is primarily to make it capable of seeing the extent of its own sinfulness so that it can repent and be purified.
For the next two stages, I will be brief, as I am merely a sinner working through purification and only know about the following stages from reading the lives of the saints:
2. Illumination (Theoria)
Illumination is the second stage of salvation, and those who are being purified through the grace of God, combined with their own efforts, see a gradual transition into this stage. Discernment and clairvoyance are sometimes associated with illumination, though they do not indicate one has fully matured into this stage nor that someone has been given a gift of clairvoyance. It is possible to receive hints of these gifts due to pursuing purity of heart, as St. Silouan the Athonite taught. One may recognize the sinful passions in others simply because they have identified the same passions within their own heart, but that does not mean they have attained to theoria.
One walking fully in illumination sees many mysteries hidden in the scriptures, in nature, and in all of life – they see how all of these things point to Christ and the heavenly Kingdom. The illuminated soul also discerns truth from lie, true theology from heresy, and may be able to see into the hearts of men. This stage is impossible to fully enter without the heart and mind being cleansed of sinful thoughts, of attachments to the comforts of the body, and of attachments to every worldly thing. One who is illuminated will see, through the nous (and not with the physical eyes), the Uncreated Light of God; they will contemplate the face of Christ.
3. Deification (Theosis)
All who continue along this path with faithfulness will, by the grace of God, enter the culminating stage called theosis, or deification, which (from my understanding) is a perpetual, uninterrupted contemplation of God and participation in His energies. This is what happens in Heaven in the age to come and is the place many saints dwell.
Second Peter 1:4 states that we will be partakers of the divine nature and 1st John 3:2-3 says, Beloved…it has not yet been revealed what we shall be, but we know that when He is revealed, we shall be like Him, for we shall see Him as He is. And everyone who has this hope in Him purifies himself, just as He is pure. There is also Matthew 5:8, Blessed are the pure in heart, for they shall see God.
All of these scriptures point us to what we were ultimately created for: union with God, divine contemplation of Him, and partaking in Him for all eternity. Many saints reached this third stage of salvation, theosis, before leaving the body. Some glowed like Moses, some could read men’s thoughts and hearts, some had “subtle” flesh and would “teleport” from one location to another (the recent St. John of Shanghai and San Francisco was known for doing that), and all contemplated the face of Christ.
So here is my meager attempt to answer your deep question. We contemplate the face of Christ by partaking in His divine nature; we partake in His nature and see His face with an illuminated spiritual eye (nous); and we illuminate the spiritual eye through the process of purification. All of this comes by the grace of Christ combined with our efforts; we work in synergy with God.