What is Faith

Faith, hope and love are the main virtues. Prelest diminishes while gradually attaining them.

Those who Work for any Sin Cannot Have True Faith

Saint Tikhon of Zadonsk. "On True Christianity". Volume 2.

I am not here talking to you, a Christian, about that faith which consists of the knowledge and keeping of right dogmas: Christians who live lawlessly also have this faith. But I am talking about the faith of the heart, living and saving (about which it was said above), this faith is not in the one who is faulty and does not live according to Christianity, even though he professes and preaches faith. Consider that Christ says: "Ye cannot serve God and mammon" (Mt. 6:24). Just as those who serve God no longer work for mammon, so slaves to mammon no longer serve God. It is impossible to work for God and mammon at the same time, according to the word of Christ. And from this we can conclude that even those who are slaves to any sin no longer serve God. And not serving God, they do not have faith, for without faith it is impossible to serve God. “Without faith it is impossible to please God,” the apostle teaches (Heb. 11:6). To serve and please God is one and the same.

He who Truly Believes Will Certainly Have Works

Venerable Seraphim of Sarov. "Spiritual Instructions to Monks and Laity".

First of all, one must believe in God, “that He is, and that He is a rewarder of them that diligently seek Him” (Heb. 11:6).

Faith, according to the teachings of St. Antiochus, is the beginning of our union with God: a true believer is a stone of the temple of God, prepared for the building of God the Father, raised to a height by the power of Jesus Christ, that is, by the Cross, [with] the help of a rope, that is, by the grace of the Holy Spirit.

“Faith without works is dead” (James 2:26); while the works of faith are: love, peace, long-suffering, mercy, humility [2] repose from all works [3], just as God rested from His works, bearing the cross and living in the spirit. Only such faith is imputed for righteousness. True faith cannot be without works; whoever truly believes will certainly have works.

[2] Cf. Gal.5:22

[3] This means, of course, not literally rest from all works, but the absence of excessive concern for them, troubles. “But seek ye first the kingdom of God, and his righteousness; and all these things shall be added unto you. Take therefore no thought for the morrow: for the morrow shall take thought for the things of itself. Sufficient unto the day is the evil thereof” (Matt. 6:33-34).