QUESTION: Where in the Psalms or prophets is the belief justified that there will be conversions in the millennial age?
ANSWER: Almost everywhere that we find the work of divine goodness contemplated. In Psa. 2:12, "Kiss the Son, lest He be angry... Blessed are all they that put their trust in Him." All conversions, past, present or future, are in this way and no other. They alone are the righteous who fear God then as now. The gospel, which actually goes out in indiscriminate grace, the Apostle vindicates to the Jewish objector in Rom. 9 and 10 by testimonies from the law, Psalms and prophets which anticipate that day. It will be the harvest. We are but a sort of firstfruits, though called to "some better thing," as in Heb. 11:40, as compared even with "the elders." But the ingathering, great as to extent, awaits that day. All must bow to the Lord, "King over all the earth," as well as "Head over all things," but all are not converted even then as Isa. 65 shows, and on a large scale Rev. 20:7-10. Previously they will have rendered but a feigned obedience. Also see Psa. 18:14.
"I sat down under His shadow with great delight."
Sol. 2:3