There is a striking difference between, on the one hand, the evangelical Protestant emphasis on the Christian's assurance of salvation - that when born-again we know we are saved by adoption into God's holy family; and, on the other hand, the Orthodox ascetic - the monk or hermit - who may continually be praying for mercy, and on guard against deception by demons, and deeply uncertain about his own eventual salvation.
On the one hand, the Orthodox monk is spiritually far more more advanced in Holiness than the usual born again evangelical; yet is is the evangelical who has assurance.
Is there a contradiction?
Since the monk is obviously Holy, and lives for Christ, yet regards his soul as in peril; Catholics might regard the confidence of the evangelical as necessarily deluded.
Evangelicals might say that monasticism is the problem, its temptations are too great; and the monk is corrupted by spiritual pride - imagining that his status (or 'job') sets him above others, and thus falling into wickedness.
(After all, Protestants must believe that monasticism is bad, and deny absolutely that it is a valid path to salvation for anyone at all; or else why did they utterly abolish monasteries? Why are there no evangelical monks or nuns?)
My understanding is that the apparent contradiction is solved if salvation is regarded as both qualitative then quantitative.
The Christian is saved, and with assurance, when converted, when born-again.
Then begins the process of sanctification or theosis - working-towards union with God during life on earth. This is the main purpose of Christian life.
The evangelical focuses on holding-onto salvation. He knows that the only thing which could lose his salvation is if he himself rejects it and turns away from God.
Therefore evangelical spirituality is - in a sense - a repetition of the born-again experience, a re-living, a rehearsal: turning to God again and again - daily, hourly. To feel, again and again, the gratitude and love of accepting Christ.
The monastic needs or wants more; wants to move forward on the path of sanctification or theosis, to become himself more like God. To start on the path which, if completed, would lead to Sainthood (as conceived by Eastern Orthodoxy; to live in Heaven and on earth simultaneously, to be an intermediary).
The monastic path is real, and really is a higher path - a more desirable goal; but it really is more hazardous.
Its hazards are profound, and amount to the loss of salvation - essentially by corruption from original sin - that is spiritual pride, causing the monastic to substitute himself for God; and corruption from personal purposive evil (Satan, devils, demons) who - it seems from numerous accounts - are attracted by spiritual ambition.
So ascetics are apparently almost-always subject to demonic attack, demonic deceptions, terrors and temptations.
Climbing a rocky mountain is more hazardous than staying on the plain below - one may be impatient to reach the top, climb too fast and become exhausted and fall into a crevice and to death; one may delude oneself that the peak has been reached and pride oneself on reaching the top when there remains much yet to climb; and one may neglect to recall that every mountain slope is the abode of devils who will try to throw the climber into volcanic fissures before they reach the summit.
The key concept is spiritual ambition.
Spiritual ambition is a good motivation; but must be balanced by humility or else will be corrupted into worldly ambition, or remain spiritual but become evil (turned away from Christ).
The true monk has great
spiritual ambition, strives for greater holiness; but any ambition can
be corrupted into pride is opened to deception in its understandings.
Under modern conditions, the perils of spiritual ambition are greater than ever. Past monks would submit to the authority of a Saint or Spiritual Father, who would watch them for signs of corruption, and ensure that the pace of sanctification did not proceed faster than the safeguarding humility which must increase to match it.
Even despite such safeguards, there were still hazards, and Holy Men fell and were lost.
Nowadays spiritual ambition is even more hazardous - and those who claim sanctification have often very obviously been corrupted, when evaluated by the discerning Christian.
The high mountains are real, but the 'low road' of evangelical Christianity may be all that is possible for most modern men.
We who live in spiritual isolation, and lack the wise authority of a Holy Father, should be wary of spiritual ambition - and fearful of losing the salvation of which we are indeed assured - assured so long as we do not ourselves cast it away.