Faith becomes concrete only when it is followed by obedience to the Commandments and doing good to others. Listen how St. James answers this question. "What does it profit, may brethren, if someone says he has faith, but does not have works? Can faith save him? If a brother or sister is naked and destitute of daily food, and one of you says to them, "Depart in peace, be warmed and filled, but you do not give them the things which are needed, what does it profit? (2:14-16). Faith without works is dead as body without life (2:17,26). Faith and good works complement each other (2:22). Similarly a man of faith will certainly obey the words of God, ie. the Commandments. Jesus has explicitly told that only the doers of his word would be saved (Mk. 7:21-27) Not every one who says to me, "Lord, Lord," shall enter the Kingdom of heaven, but he who does the will of my father in Heaven" (Mt. 7:21, Ct. Lk. 6:46) . In the end of the world, 'the Son of man will come in the glory of His Father with his angels, and then He will reward each according to his works" (Mt. 16:27, ct. 25.31-46) To the lawyer who asks Jesus what he must do to attain eternal life, Jesus tells to keep the Commandment of love - love of God and love of the neighbour (Lk. 10:25-28). St Paul says that we shall not grow weary or do not lose heart while doing good (Gal 6:9). "Therefore, as we have opportunity, let us do good to all, especially to those who are in the household of faith" (Gal. 6:10).
To sum up, to attain salvation, one has to live his faith in Christ, in the Church, obeying God's Commandments, doing good to others, receiving the sacraments, keeping the genuine traditions of the Church and adhering to her teaching authority.