Do we merit eternal life through our good works?
Scripture tells us that God does reward us for our good works (2 John 8, Revelation 22:12 etc.). The kind of good works are mainly acts of charity and love (Proverbs 25:21-22, Marks 9:41, Luke 6:35) including almsgiving (Matthew 6:3-4), but also being righteous (Psalm 18:20, Proverbs 11:18), obeying God’s commandments (Proverbs 13:13), prayer (Matthew 6:6), perseverance under persecution (Luke 6:23) and fasting (Matthew 6:18). They must be done without any personal motives (cf. Matthew 6:2, 5, 16), they must go beyond the norm (Matthew 5:44-46) and must be based on love or charity (1 Corinthians 13:3). What kind of reward God gives us? Scripture says that love covers a multitude of sins (1 Peter 4:8) and that almsgiving delivers from death and purges sins (Tobit 4:10, 12:9, Sirach 3:30; note that Protestants do not accept Tobit and Sirach as Scripture). By loyalty and faithfulness iniquity is atoned for (Proverbs 16:6, RSV). Daniel told king Nebuchadnezzar to break-off his sins by practising righteousness and his iniquities by showing mercy to the oppressed; by doing so God might lengthen his tranquillity (Daniel 4:27). Because Ahab humbled himself and fasted, God will not bring evil in his days but in his son’s days (1 Kings 21:27-29). Cornelius gave alms and prayed to God and God sent Peter to tell him and his family the good news and gave them the gift of the Holy Spirit (Acts 10:1-6, 44-48). Does God reward us with eternal life for our good works? Scripture says:
Do not marvel at this; for the hour is coming when all who are in the tombs will hear his voice and come forth, those who have done good, to the resurrection of life, and those who have done evil, to the resurrection of judgment.
For he will render to every man according to his works: to those who by patience in well-doing seek for glory and honour and immortality, he will give eternal life; but for those who are factious and do not obey the truth, but obey wickedness, there will be wrath and fury. There will be tribulation and distress for every human being who does evil, the Jews first and also the Greek, but glory and honour and peace for everyone who does good, the Jews first and also the Greek.
Do not be deceived; God is not mocked, for whatever a man sows, that he will also reap. For he who sows to his own flesh will from the flesh reap corruption; but he who sows to the Spirit will from the Spirit reap eternal life.
Thus Scripture does say that we do merit eternal life from good works and that’s what the Catholic Church teaches.
If any one saith, that the just ought not, for their good works done in God, to expect and hope for an eternal recompense from God, through His mercy and the merit of Jesus Christ, if so be that they persevere to the end in well doing and in keeping the divine commandments; let him be anathema.
Council of Trent, Canon XXVI of the Decrees on Justification
The argument against the merits from our good works is based on what Jesus said in:
Will any one of you, who has a servant plowing or keeping sheep, say to him when he has come in from the field, `Come at once and sit down at table’? Will he not rather say to him, ‘Prepare supper for me, and gird yourself and serve me, till I eat and drink; and afterward you shall eat and drink’? Does he thank the servant because he did what was commanded? So you also, when you have done all that is commanded you, say, `We are unworthy servants; we have only done what was our duty
But if this parable is interpreted to mean there are no merits from our good works then it contradicts many verses cited earlier that say otherwise. In this parable Christ reminds us that our merits come from God and are to be regarded as God’s gift, not something we deserve and that’s exactly what Catholics believe. Catholics consider merits of good works as gift from God because we cannot do it unless we are first moved by His Grace.