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 SarovThose who have truly decided to serve the Lord God should practice the remembrance of God and uninterrupted prayer to Jesus Christ, mentally saying: Lord Jesus Christ, Son of God, have mercy on me, a sinner.
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 SarovThe true aim of our Christian life consists in the acquisition of the Holy Spirit of God. As for fasts, and vigils, and prayer, and almsgiving, and every good deed done for Christ's sake, they are only means of acquiring the Holy Spirit of God.
Seraphim of Sarov... the people who, in spite of the bonds of sin which fetter them and hinder them (by constraint and by inciting them to new sins), come to Him, our Savior, with perfect repentance for tormenting Him, who despise all the strength of the fetters of sin and force themselves to break their bonds ? such people at last actually appear before the face of God made whiter than snow by His grace. 'Come, says the Lord: Though your sins be as scarlet, I will make them whiter than snow' (Isa. 1:18).
Seraphim of Sarov