Faith is truly a gift, gained for us through Christ's advent. But this does not abolish our freedom or responsibility. God desires of us not only faith but action too.
As earth thrown over it extinguishes a fire burning in a stove, so worldly cares and every kind of attachment to something, however small and insignificant, destroy the warmth of the heart which was there at first.
Faith is the sincere confession that God, Who is worshipped in the Trinity, Who created all things and provides for all, saves us who are fallen, through the power of the death on the Cross of the incarnate Son of God, by the grace of the Most Holy Spirit in His Holy Church. The beginnings of renewal, which are established in this life, will appear in all their glory in the future age, in a way that the mind cannot comprehend nor the tongue express.
Faith is an eye that enlightens every conscience, and imparts understanding; for the Prophet saith, And if ye believe not, ye shall not understand (Is. vii, 9).
In the heart is the will; in the heart is love; in the heart is the mind--in the heart is the image of the divine Trinity. The heart is the home of the Father, the altar of the Son and the workshop of the Holy Spirit. God wants our hearts: Son, give Me thy heart. Oh, my brother, above and beyond all else that you keep safe, guard your heart. Let the mountains be overthrown and the seas dried up; let friends forsake you and riches betray you; let your body be eaten by worms; let the world pour on you all the scorn of which it is capable--and do not fear. Only guard your heart; guard it and make it cleave to the Lord; give it into His keeping. Life flows from the heart; but whence comes this life in the heart, unless it is the abode of the breath of the Lord and Source of life-God? Oh, my brother, the Spirit of God Himself can, when He so desires, dwell in the human heart. He not only can, but wills to do so. Only, He waits for you to prepare your heart for Him; to make it into a temple, for God the Holy Spirit only lives in a temple. As a snake protects its head, so, my son, guard your heart. For the life that comes from the living God enters into it and flows forth from it.
There is nothing impossible unto those who believe; lively and unshaken faith can accomplish great miracles in the twinkling of an eye. Besides, even without our sincere and firm faith, miracles are accomplished, such as the miracles of the sacraments; for God's Mystery is always accomplished, even though we were incredulous or unbelieving at the time of its celebration. 'Shall their unbelief make the faith of God without effect?' (Rom. 3:3). Our wickedness shall not overpower the unspeakable goodness and mercy of God; our dullness shall not overpower God's wisdom, nor our infirmity God's omnipotence.
Someone may say: 'I have faith, and faith suffices for salvation.' St. James gives him the answer: 'Even the demons believe, and shudder. Faith without works is dead.' (James 2:17-19)
According to the teaching of the Fathers, any impression which, touching the heart, fills it with a great irritation, must come from the region of passions. Therefore impulses which spring from the heart should not be followed at once, but only after careful examination and fervent prayer. God preserve us from a blind heart! It is well known that passions do blind the heart and screen the shining sun of the mind that we should all strive to gaze at.
Not every man is wakened to wonder by what is said spiritually and has great power concealed in it. A word concerning virtue has need of a heart unbusied with the earth and its converse.
Intemperance and attachment to things cause torrents of passions to flood the soil of the heart and deposit there all the mud and filth of thoughts, thus confusing the mind, darkening the heart and weighing down the body. In the heart and the soul they produce negligence, darkness and death and deprive them of the feeling and disposition natural to them.
If you fast regularly, do not be inflated with pride; if you think highly of yourself because of it, then you had better eat meat. It is better for a man to eat meat than to be inflated with pride and glorify himself.