What is required of people in the age of grace?
In the age of grace, all that is required is to believe the Gospel. Nothing else is demanded of people; God does everything else. This stands in contrast to earlier ages, where Israel's history and rejection of Messiah led God to open the windows of heaven and extend grace.
Les explains that as Israel came up through history, they rejected their Messiah and the promised Kingdom, so God did something different: He opened the windows of heaven, what we call the grace of God. In this age of grace, the only requirement is to believe the Gospel; that's all. When a person believes the Gospel, God does everything else—something unheard of throughout the previous thousand years of human history. Les also notes that this age of grace has ended, and God will pour out His wrath in the final seven years of dealing with Israel's prophecy, before the millennial reign.