The Holy Fathers say that as angels are light to monastics, so true monastics are light to people.

What does the word "light" mean here?

That monastics are those who preserve the high criterion, that is, the martyric ethos of Christian struggle and life in the Church. And moreover, that they ought to be guides, show the way of spiritual growth to people with their very existence, their deeds, their word – with their whole life. Hence, monastics ought to be light to laity, to the people living Christian life in the world. This, in a way, puts the monastic order in the Church in place of prophetic ministry: as the Prophets in the Old Testament announced the coming of Christ to the people and showed them the way of being in constant communion with God and never estranging from Him, so monastics today have the same role in the life of the Church. And indeed, if monastics fulfil their calling, they become light and support to all that harbour their hope in God.

A true monastic is the one who has gone through the way of purification of his heart from passions and sin and has ascended to the second degree of spiritual growth – illumination of the mind. At this spiritual level the monastic's mind, owing to the openness of the heart, can descend in the heart and perform the prayer there. Staying prayerfully in the heart, the mind partakes of the Divine grace that every man receives at Holy Baptism. Here, in the heart, the monastic's mind illumines transformed by this grace and therefore this degree of spiritual growth is called illumination of the mind. Owing to the illumination of the mind, the monastic comprehends the mysteries of life in general, the mysteries of God and of the Holy Scriptures, the mystery of the Church. Hence he can show his way and attainment to other people and lead them along this way, since he himself has gone through it and knows it well...

 ...Our love towards people is the simplest indicator of how we grow in Christ.

 (Metropolitan Nahum of Strumica, excerpt from the essay On Essence of Monastic Life)