God is a fire that warms and kindles the heart and inward parts. Hence, if we feel in our hearts the cold which comes from the devil - for the devil is cold - let us call on the Lord. He will come to warm our hearts with perfect love, not only for Him but also for our neighbor, and the cold of him who hates the good will flee before the heat of His countenance.
Seraphim of SarovWhen a man receives something Divine, in his heart he rejoices; but when he receives something diabolic, he is disturbed. The Christian heart, when it has received something Divine, does not demand anything else in order to convince it that this is precisely from the Lord; but by that very effect it is convinced that this is heavenly, for it senses within itself spiritual fruits: love, joy, peace, and the rest (cf. Gal. 5:22).
Seraphim of SarovPrayer, fasting, vigils, and all other Christian practices, however good they may be in themselves, certainly do not constitute the aim of our Christian life: they are but the indispensable means of attaining that aim. For the true aim of the Christian life is the acquisition of the Holy Spirit of God. As for fasts, vigils, prayer and almsgiving, and other good works done in the name of Christ, they are only the means of acquiring the Holy Spirit of God. Note well that it is only good works done in the name of Christ that bring us the fruits of the Spirit.
Seraphim of SarovOh, if you only knew what joy, what sweetness awaits a righteous soul in Heaven! You would decide in this mortal life to bear any sorrows, persecutions and slander with gratitude. If this very cell of ours was filled with worms, and these worms were to eat our flesh for our entire life on earth, we should agree to it with total desire, in order not to lose, by any chance, that heavenly joy which God has prepared for those who love Him.
Seraphim of SarovThe reading of the word of God should be performed in solitude, in order that the whole mind of the reader might be plunged into the truths of the Holy Scripture, and that from this he might receive warmth, which in solitude produces tears; from these a man is wholly warmed and is filled with spiritual gifts, which rejoice the mind and heart more than any word.
Seraphim of Sarov