"Do not be deceived, God is not mocked; for whatever a man sows, this he will also reap" (Gal 6:7). God has built a cause-and-effect into life which automatically judges. "'Vengeance is Mine, and retribution, in due time their foot will slip; for the day of their calamity is near'" (Dt 32:35). "'I will repay', says the Lord" (Ro 12:19). "God is not one to show partiality" (Ac 10:34). There is "no injustice with God" (Ro 9:14). He is "the one who impartially judges according to each one's work" (1Pe 1:17). "We know that the judgment of God rightly falls upon those who practice such things" (Ro 2:2). "How unsearchable are His judgments" (Rev 15:3). "'Righteous and true are your ways'" (:3).
What you do makes a difference because it determines whether you will "inherit the kingdom" (Mt 25:34). What qualifies is if you help feed, clothe and house people, and visit people when they are sick or in prison (:35-36). They "were judged from the things which were written in the books, according to their deeds" (Rev 20:12). It should make one take notice that his actions are actually recorded. "Whatever good thing each one does, he will receive back from the Lord" (Eph 6:8). "You recompense a man according to his work" (Ps 62:12). Paul quotes this regarding "the day of wrath and revelation of the righteousness judgment of God, who WILL RENDER TO EACH PERSON ACCORDING TO HIS DEEDS" (Ro 2:5-6). Jesus says "'My reward is with Me, to render to every man according to what he has done'" (Rev 22:12). "By perseverance in doing good . . . [you receive] eternal life" (Ro 2:7). "This is the promise which He Himself made to us: eternal life" (1Jn 2:25). "'This is eternal life, that they may know You, the only true God, and Jesus Christ whom You have sent'" (Jn 17:3). "'For God so loved the world, that He gave His only begotten Son, that whoever believes in Him shall not perish, but have eternal life'" (3:16). But "He who does not have the Son of God does not have the life" (1Jn 5:12).
God is "the Judge of all" (Heb 12:23) but "not even the Father judges anyone, but He has given all judgment to the Son" (Jn 5:22). He is "the One who has been appointed by God a Judge of the living and the dead" (Ac 10:42). "God will judge the secrets of men through Christ Jesus" (Ro 2:16). "There is nothing covered up that will not be revealed, and hidden that will not be known" (Lk 12:2). Is there a time for this? "We will all stand before the judgment seat of God" (Ro 14:10). "He has fixed a day in which He will judge the world in righteousness through a Man whom He has appointed, having furnished proof to all men by raising Him from the dead" (Ac 17:31). "Having overlooked the times of ignorance, God is now declaring to men that all people everywhere should repent" (:30). He "is patient toward you, not wishing for any to perish but for all to come to repentance" (2Pe 3:9). "He ordered [the Apostles] to preach to the people and solemnly to testify" (Ac 10:42) about it. "The Lord Jesus will be revealed from heaven . . . dealing out retribution to those who do not know God and to those who do not obey the gospel of our Lord Jesus" (2Th 1:7-8). "'Do not fear those who kill the body but are unable to kill the soul; but rather fear Him who is able to destroy both soul and body in hell'" (Mt 10:28). "The wages of sin is death, but the free gift of God is eternal life in Christ Jesus our Lord" (Ro 6:23). "'My sheep hear My voice, and I know them, and they follow Me; and I give eternal life to them, and they will never perish'" (Jn 10:27-28). "'In My Father's house are many dwelling places; if it were not so, I would have told you; for I go to prepare a place for you'" (Jn 14:2). However, "'He will also say to those on His left, 'Depart from Me, accursed ones, into eternal fire which has been prepared for the devil and his angels''" (Mt 25:41).
Is God's judgment complicated because there are so many different people and religions? Perhaps it can be simplified to just the Jew and the Gentile. God "desires all men to be saved" (1Ti 2:4). It is evaluated when we all "appear before the judgment seat of Christ" (2Co 5:10). "All the nations will be gathered before Him" (Mt 25:32). It is "on the day when . . . God will judge the secrets of men through Christ Jesus" (Ro 2:16). God has clearly revealed his divinity and power such that it is obvious and "they are without excuse" (1:20) if they don't concur. This is at the "great white throne" (Rev 20:11). "The dead were judged from the things which were written in the books, according to their deeds" (:12). "He will separate them from one another" (Mt 25:32) and "say to those on His right, 'Come . . . inherit the kingdom'" (:34) and "those on His left, 'Depart from Me'" (:41). "Those who did the good deeds [will go] to a resurrection of life, [and] those who committed the evil deeds to a resurrection of judgment " (Jn 5:29). We know God is fair because he "does not show partiality" (Dt 10:17) and "in every nation the man who fears Him and does what is right is welcome to Him" (Ac 10:34-35).
Judgment and reward are synonymous because "My reward is with Me" (Rev 22:12). God will "render to every man according to what he has done" (:12). He will "search the heart, . . . test the mind . . . [and] give to each man according to his ways, according to the results of his deeds" (Jer 17:10). Each will "be recompensed for his deeds in the body, according to what he has done" (2Co 5:10). There are principles God judges by. "Whatever a man sows, this he will also reap. For the one who sows to his own flesh will from the flesh reap corruption, but the one who sows to the Spirit will from the Spirit reap eternal life" (Gal 6:7-8).