By St. Nikolai Velimirovich
"Guard your heart!" These words were spoken in the past by experienced ascetics.
Father John of Kronstadt says the same thing in our days: "The heart is refined, spiritual and heavenly by nature; guard it. Do not overburden it, do not make it earthly; be temperate to the utmost in food and drink and, in general, in bodily pleasures. The heart is the temple of God. `If anyone destroys God's temple, God will destroy that person'" (1 Corinthians 3:17).
Spiritual experience in ancient times and spiritual experience in our time is identical, under the condition that the confession of faith is identical. Heavenly knowledge, to which the ascetics of old arrived, does not differ from the heavenly knowledge to which the ascetics of today arrive. For as Christ is the same today and tomorrow so it is the same with human nature.
What is important: the human heart is the same; his thirst, and his hunger, is the same; and nothing is able to satisfy him but the glory, power and riches of God.
About Christ In the Hearts of the Faithful
"And that Christ may dwell in your hearts through faith" (Ephesians 3:17).
That person does not have Christ who only has Him on his tongue. Neither does that person have Christ who has Him only on paper. Neither does that person have Christ who has Him only on the wall. Neither does that person have Christ that has Him in the museum of the past. That person, in truth, has Christ who has Him in his heart. For Christ is Love and the throne of love is the heart.
If Christ is in your heart then, for you, He is God. If He is only on your tongue, or on paper or on a wall, or in the museum of the past and even though you call Him God, for you, He is but a toy. Beware then, O man, for no one can play around with God without punishment.
The heart apparently is a narrow organ, but God can dwell in it. When God dwells in it, then it is filled and overly filled and nothing else can position itself in it. If, however, the whole world were to settle in it, it remains empty without God.
Brethren, let Christ, the resurrected and living Lord, pour faith into your hearts and your hearts will be filled and overly filled. He cannot enter and dwell into your hearts except through your faith. If you do not possess faith, Christ will remain only on your tongue or on your paper or on your wall or in the museum of the past. What kind of benefit do you have from that? What kind of benefit do you have to hold life on your tongue and death in your heart? For, if you hold the world in your heart and Christ on your tongue, you hold death in your heart and life on your tongue. Water on the tongue of the thirsty does not help. Lower the living Christ into your heart and you will be permeated with the truth and you will sense unspeakable sweetness.
O resurrected Lord, cleanse our hearts from the deadly guests who dwell in it and You Yourself take up dwelling in it, that we may live and glorify You. Amen.