You do not understand what a good work is. A good work is Christ's work.
The Apostles good work was to spread the gospel. Is this their work or Christ's work which they were doing? Is this the apostles work of salvation or Christ's?
Christ is who makes us partakers of His work through His grace.
Ephesians
8For it is by grace you have been saved, through faithand this not from yourselves, it is the gift of God 9not by works, so that no one can boast. 10For we are God's workmanship, created in Christ Jesus to do good works, which God prepared in advance for us to do.
In the Communion of Saints
1474 The Christian who seeks to purify himself of his sin and to become holy with the help of God's grace is not alone. "The life of each of God's children is
joined in Christ and through Christ in a wonderful way to the life of all the other Christian brethren in the supernatural unity of the Mystical Body of Christ, as in a single mystical person."
86
1475 In the communion of saints, "a perennial link of charity exists between the faithful who have already reached their heavenly home, those who are expiating their sins in purgatory and those who are still pilgrims on earth. between them there is, too, an abundant exchange of all good things."
87 In this wonderful exchange, the holiness of one profits others, well beyond the harm that the sin of one could cause others. Thus recourse to the communion of saints lets the contrite sinner be more promptly and efficaciously purified of the punishments for sin.
1476 We also call these spiritual goods of the communion of saints the
Church's treasury, which is "not the sum total of the material goods which have accumulated during the course of the centuries. On the contrary the 'treasury of the Church' is the infinite value, which can never be exhausted, which
Christ's merits have before God. They were offered so that the whole of mankind could be set free from sin and attain communion with the Father. In Christ, the Redeemer himself, the satisfactions and merits of his Redemption exist and find their effficacy." 88