What is the great danger of grumbling against God and His servants because of perceived injustices to us, especially in regard to envy? See Exo 17:3, Num 11:1, 14:26-30, 1Co 10:10-11; cf. Luk 15:29, Rom 9:30-32, 10:19-21, 11:7-11. Why is it always wrong to grumble against God supposing He is treating us unfairly? See Rom 8:28; cf. Deut 8:3,5. Even when it is contrary to the expectations of our fallen nature, why is it a good thing that God is working in us when He reveals to us His own nature and character? See Joh 17:3. In regard to the perceived unfairness that the first workers were grumbling about against the landowner, were they in fact being treated unjustly? Why not? See Mat 20:13-15. In regard to the spiritual meaning of the parable, what is the equal reward of the laborers? See Mat 19:16,29.
From the heavenly perspective of God’s unfolding plan of salvation, in what way have the Jews born more of a “burden and the scorching heat of the day” (Mat 20:12) than the Gentiles? Cf. again Luk 15:29, and consider what people throughout history has been the most despised and persecuted. In what way were the Gentiles made equal to the Jews that so provoked the Jews to envy? See Eph 2:13, 3:6; cf. Luk 15:22-24. In what ways did the first disciples and especially the apostles bear more of the burden than others who would come to Jesus, not only later in history but even in their own day? Cf. Luk 23:39-43 and explain how the thief on the cross is another example of the point of Jesus’ parable articulated in Mat 19:30 and 20:16. Consider too the possibility that the rich man from Mat 19 turned to Christ in his last days as his wealth was lost in the Roman destruction of the nation; how might the apostles who bore the heat of persecutions and the burden of establishing the Church have felt to have him receive the same reward as they, after pursuing his course of life in the world for so long?
In what way do those who are born into a Christian home and serve God faithfully all their lives bear more of a burden than those who are saved later in life? Are we in fact serving God faithfully, laboring hard in the vineyard and bearing any burden in the heat of the day? Or are we more like the son who told the Father he would go work in the vineyard but then didn’t? See Mat 21:28-32. Have we the same love of God to see even those who have acted wickedly and rejected the truth their whole lives come to salvation and receive the same reward as us? Or have we become like the Jews in wanting heaven all to ourselves, indifferent to the lost souls of humanity because like the Jews we have labored hard and in envy cannot imagine how others who have not labored as hard could receive the same reward as us?
When the landowner answered the grumbling workers, did he address himself to all of them? See Mat 20:13. Who might this “one” in particular represent, and why would he have reason to grumble about bearing an extra burden in the heat of the day? See Mat 19:27. In what way was Peter later forced to come to grips with the significance and meaning of this parable? See Act 10:28,44-48, Gal 2:11-12, Act 15:6-11. Which apostle suffered more and bore an even greater burden than all the rest of the apostles, and why? See 2Co 11:16-27, Act 9:15-16, 22:21-22. Although he had reason to boast and expect a greater reward than others for the burdens he bore, how did Paul guard against that temptation? See 2Co 12:1-11, 1Co 15:9, Eph 3:8, 1Ti 1:12-15. Should we not also continually remind ourselves who we really are without Christ? Cf. Luk 17:7-10.
As the workers in this parable agreed with the landowner to work in His vineyard for a reward, in what way do those who are called by the god of this age also agree to work in his field for a reward? What is his field, and what is the reward for which they agree to work? See Luk 4:5-7, Eph 2:2. How does that contrast with the reward for which the workers in God’s vineyard agree to work? See Joh 6:27, 1Jo 2:15-17; cf. Mat 6:2,5,16, Luk 6:21-26, 16:25. If we have agreed with God for an eternal reward in heaven, should we expect a temporal reward here on earth? Should those who have agreed with the god of this age for a temporal reward on earth expect an eternal reward in heaven? Again, whom then shall we serve? See Jos 24:15.