I encounter the Bible term “Outer darkness where there will be weeping and gnashing of teeth” in various places in the scripture, but I don't know what this phrase means. For example, where does the wicked servant in the story of talents in Matthew 25 actually end up?
In Matthew’s parables, he occasionally records Jesus describing an individual going to a place of outer darkness. This phrase is a description of Hell (and eventually the Lake of Fire) based on the context. For example, Jesus declared that the unbelieving Jews would go to this place instead of the Kingdom:
Matt. 8:10 Now when Jesus heard this, He marveled and said to those who were following, “Truly I say to you, I have not found such great faith with anyone in Israel.
Matt. 8:11 “I say to you that many will come from east and west, and recline at the table with Abraham, Isaac and Jacob in the kingdom of heaven;
Matt. 8:12 but the sons of the kingdom will be cast out into the outer darkness; in that place there will be weeping and gnashing of teeth.”
In Matthew 25, the lone slave who goes to outer darkness represents the unbeliever who never truly knew the Lord, in keeping with Matthew 7:
Matt. 7:21 “ Not everyone who says to Me, ‘Lord, Lord,’ will enter the kingdom of heaven, but he who does the will of My Father who is in heaven will enter.
Matt. 7:22 “ Many will say to Me on that day, ‘Lord, Lord, did we not prophesy in Your name, and in Your name cast out demons, and in Your name perform many miracles?’
Matt. 7:23 “And then I will declare to them, ‘I never knew you; DEPART FROM ME, YOU WHO PRACTICE LAWLESSNESS.’
There will be some who claim to know the Lord but are not truly born again. The parable in Matthew 25 is an example of one such person. You can learn more about the parables in Matthew 25 by listening to Lesson 5D & 5E of our Revelation Bible study.