What is The Last Judgment?
God has appointed a day when He will judge the world in righteousness by Jesus Christ, to whom the Father has given all power and judgment. On that day, not only the apostate angels will be judged, but also all people who have lived on the earth. They will appear before Christ's judgment throne to give an account of their thoughts, words, and deeds, and to receive [judgment] according to what they have done in the body, whether good or evil.
God's purpose in appointing this day is to show forth the glory of His mercy in the eternal salvation of the elect, and His justice in the eternal damnation of the reprobate who are wicked and disobedient. Then the righteous will inherit eternal life and receive fullness of joy and glory with eternal reward in the presence of the Lord. But the wicked, who do not know God and do not obey the gospel of Jesus Christ, will be banished to eternal torment, and be punished with eternal destruction, shut out from the presence of the Lord and from the glory of His power.
Christ wants us to be firmly persuaded that there will be a day of judgment, both to deter everyone from sin, and to give greater comfort to the godly in their adversity. But He has kept the date a secret, so that people may shake off all self-confidence and always be watchful, because they know not at what hour the Lord will come. So they should always be prepared to say, 'Amen. Come, Lord Jesus!' Amen.