The candles burning on the altar represent the non-created Light of the Trinity, for the Lord dwells in an unapproachable light. They also represent the fire of Divinity which destroys our ungodliness and sins. The candles lit before the icons of the Savior signify that He is the True Light which lighteth every man that cometh into the world (John 1:9); at the same time, He is a Fire which engulfs and revives our souls and bodies.
It is more serious to lose hope than to sin. The traitor Judas was a defeatist, inexperienced in spiritual warfare; as a result he was reduced to despair by the enemy's onslaught, and he went and hanged himself. Peter, on the other hand, was a firm rock: although brought down by a terrible fall, yet because of his experience in spiritual warfare he was not broken by despair, but leaping up he shed bitter tears from a contrite and humiliated heart. And as soon as our enemy saw them, he recoiled as if his eyes had been burnt by searing flames, and he took flight...
The candles lit before icons of saints reflect their ardent love for God for Whose sake they gave up everything that man prizes in life, including their very lives, as did the holy apostles, martyrs and others. These candles also mean that these saints are lamps burning for us and providing light for us by their own saintly living, their virtues and their ardent intercession for us before God through their constant prayers by day and night. The burning candles also stand for our ardent zeal and the sincere sacrifice we make out of reverence and gratitude to them for their solicitude on our behalf before God.
The candles lit before the icons of the Theotokos are a symbol of the fact that She is the Mother of the Unapproachable Light, and also of Her most pure and burning love for God and Her love for mankind.
You can see that a city is prosperous by the wealth of goods for sale in the market. Land too we call prosperous if it bears rich fruit. And so also the soul may be counted prosperous if it is full of good works of every kind. But first of all it has to be farmed energetically. Then it must be watered by abundant streams of heavenly grace for it to bring forth fruit, some thirty fold, some sixty fold, and some a hundred fold. The soul only acquires goodness and the capacity of fulfilling its duties if it has the grace of God On the other hand, what is uglier or more disgusting than a soul given over to base passions? Look at the hot-headed person: he is like a wild beast. Consider the slave of lust or gluttony: who can bear the sight of him? Pity the victim of melancholy whose spirit is totally prostrated. It is for us to seek to acquire beauty so that the Bridegroom, the Lord, may welcome us into his presence and say, “You are utterly fair, my love, and there is no flaw in you.” (Song of Sol 4:7)