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  repose from all works , 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.
 Cf. Gal.5:22
 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).