“Every warning God gives of judgement must be taken seriously, including those given to professing Christians. If we play with some secret sin we need to heed the warning of self-deception. ‘Do not be deceived: God cannot be mocked. A man reaps what he sows. The one who sows to please his sinful nature, from that nature will reap destruction; the one who sows to please the Spirit, from the Spirit will reap eternal life’ (Gal. 6:7–8). The Lord Jesus himself warns professing Christians, ‘Not everyone who says to me, “Lord, Lord”, will enter the kingdom of heaven, but only he who does the will of my Father who is in heaven. Many will say to me on that day, “Lord, Lord, did we not prophesy in your name, and in your name drive out demons and perform many miracles?” Then I will tell them plainly, “I never knew you. Away from me, you evildoers!” ’ (Matt. 7:21–23).
Understanding that the Lord’s warnings of punishment are no idle threat gives a responsibility to share his warnings with others. God’s warnings are an essential part of the gospel of our Lord Jesus Christ. Christians are called to be like watchmen on a city wall who warn inhabitants of the danger that is coming (see Ezek. 3:16–19). People need to know that God is right to be angry, that God is right to punish sin, and that the day of his wrath is coming. His warnings are themselves acts of kindness and patience, calling people to repentance. The Lord is slow to anger. His wrath does not come quickly. But it will come and those who believe his warnings must proclaim them.
Some may laugh at the suggestion that God will punish sin. Others, hearing his warnings, will think they apply to others, but not to them. The reaction of others must not stop those who take his warnings seriously from proclaiming them. Ruth 1:1 illustrates that the Lord’s warnings of punishment are no idle threat.”
Jonathan Prime, Opening up Ruth, Opening Up Commentary (Leominster: Day One Publications, 2007), 23–24.