The question, “What about the eternal punishment of Matthew 25:46?” is covered in Are you saying there is no “punishment” for the unsaved? But to state very briefly, the punishment (or wages) of sin according to scripture is always death. Romans 6:23 and many other scriptures state this very clearly, “The wages of sin is death.” And how long will this punishment of death last? Remember, Matthew 25:46 verse is taking place while they are standing before God and know that He can bring anyone back from death. Perhaps God will raise them back to life to enjoy the Kingdom they will clearly see in front of them? No, they will be told they will miss out on the joy of being alive forever. Their sentence and punishment of death will last forever. That is why he tells them in Matthew 25:46 that it is eternal punishment. It is a complete shame that believers have such a low view on the gift of life and existence from God that they do not believe having a person’s life removed is a punishment. Yet it is a punishment. And that punishment will last forever.