Today the Orthodox Church celebrates the Day of the Holy Spirit. The Epistle to the Ephesians reminds us that 'the fruit of the Spirit is in all goodness, righteousness, and truth' (v. 9), and calls us to 'be filled with the Spirit' (v. 18). The apostle Paul calls this new state of the human being 'light in the Lord'; the apostle John also turns to this image of light when he speaks of brotherly love among believers (1 John 2:10). In the spirit of love we are called to 'seek those who have gone astray' (Matt 18:10-14), to resolve problems in our relationships (Matt 18:15-18), and, finally, to receive God's grace in unanimous prayer in the name of Christ and in His presence, just as we were promised.

As the Savior's words show, the question of faith is directly connected with the question of spiritual life as such. What does it mean to increase faith? How did the disciples themselves understand an increase in faith? They must have meant something connected with the confidence they experienced when, at their Teacher's command, they preached the Kingdom and joyfully saw that not only people, but also spirits obeyed them. In those days, this sense of power was usually associated with faith, with its presence or absence. Jesus, however, is speaking of something somewhat different. He speaks of faith as a spiritual state. Precisely and only a spiritual one. After all, any manifestation of inner strength in a person is a natural phenomenon as much as a spiritual one. Here there is not only the spiritual impulse as such, not intention alone, but also nature and the psyche, which also respond to spiritual influence. But Jesus speaks only of the spirit. Only of the will. Only of intention.

Spirit is not nature. Quantitative measurements are impossible here. Spirit, or will, does not come in larger or smaller amounts. If the will is not fragmented, if it is not scattered through inner, psychological space or outer, physical space, it has absolute force. Not in the whole universe created by God, of course; only the will of the Creator Himself has that kind of power. But at one concrete point, it certainly does. That is why faith the size of a mustard seed is enough to move a mountain from its place. Faith here is not inner strength, and certainly not conviction about anything at all, but the fullness of relationship with God. It is that same fullness which, when directed toward creation, becomes the source of an infinitely powerful force, if only it is fully concentrated on something specific. But reaching that kind of concentration is not easy. No psychological techniques will help here.

This concentration is a derivative of that fullness of the life of the Kingdom which, in principle, has been opened after Christ's coming to everyone who seeks. It is the same fullness whose experience lets a person serve without counting merit: we have done what we were supposed to do; we are only servants who do not deserve a reward. It is the fullness in which one understands that every sin is absolutely destructive, and that, although sin is inevitable in the fallen world, complicity in it is always an existential catastrophe for a resident of the Kingdom. It is the fullness that is possible only in the Kingdom and without which there is no Kingdom. The fullness for which alone it makes sense to live.

How can one know what is pleasing to God? How should one act so as not to be guilty before Him? These questions are not simple and, most importantly, far from idle, for very much in our life depends on the practical answer to them. In the letter to the Ephesians the apostle Paul uses a remarkable verb, translated into Russian as "test." It really does mean "to test, check, find out the truth about something." This verb was used when checking recruits' fitness for military service; in those times there was no medical commission, and they checked the ability to throw a spear and the like. This means the apostle calls us to act as children of light, checking our actions "for fitness," checking whether they will be pleasing before the face of the Almighty.

In the Greek text all these words form one sentence, and this is important. A test must be based on criteria, and therefore the apostle names the main criterion: the fruits of the Holy Spirit. Thus, what is pleasing to God is what can be called the fruits of the action of the Holy Spirit in our life. Chiefly this is all goodness, righteousness, and truth. Perhaps by these closely related words the apostle is trying to convey something that cannot fit into words. Modern language designates this with the rather vague term "good." Precisely what we call good, its growth and therefore the diminishing of evil, becomes for the apostle Paul the criterion of whether our actions and life itself are pleasing to God.