What did Jesus mean when He said, 'I never knew you. Depart from me'?

TL;DR:

When Jesus says “I never knew you. Depart from me,” he is referring to those who put on a show of faith but lack true saving faith. God calls us to true, genuine faith.

The Bible teaches that a mere outward show of faith is very different from true, saving faith. The Old Testament records many times when the ancient Israelites demonstrated that their heart wasn’t with God despite seeming to follow the rituals of the Mosaic law (Mallachi 1:8). Time and again, God’s prophets warned and condemned Judah and Israel for the hardness of their hearts (Isaiah 29:13; Micah 6:8). Jesus often did the same in the New Testament against the religious leaders who exalted themselves rather than God. An example of this is the last section of Matthew 7, which contrasts true faith with insincere shows of faith. Jesus illustrated the difference by using the metaphor of the type of fruit a tree produces—either good or bad. With this, He taught how to recognize true believers (Matthew 7:15–20). But He goes on to explain that even those whose actions seem right may be hiding a hard heart. Jesus warned against such false prophets who claim to be believers, who may say all the right things or have displayed miraculous power, but don’t truly belong to God (Matthew 7:15). Our omniscient Lord can read hearts, and will eventually separate the sheep from the goats (Matthew 25:32–33). Those who love the Lord will not have to hear Him say on judgment day, “‘I never knew you; depart from me, you workers of lawlessness” (Matthew 7:22–23).

from the old testament

In Isaiah 29:13, the Lord calls out the hypocrisy of those who put on a show of following Him but who do not love Him: “And the Lord said: ‘Because this people draw near with their mouth and honor me with their lips, while their hearts are far from me, and their fear of me is a commandment taught by men.” The Lord called out Judah for not honoring God in their hearts.
Micah 6:8 reveals what the Lord wants from His people: “He has told you, O man, what is good; and what does the Lord require of you but to do justice, and to love kindness, and to walk humbly with your God?” The nation of Israel thought the rituals they performed would make up for their immorality. But underlying the Mosaic law was a moral code that revealed God’s holiness and called His people to live in a way that reflects this. The Israelites’ rituals meant nothing because they weren’t following the spirit of the moral code.

from the new testament

In Matthew 7:22–23 after warning of false prophets, Jesus says of judgment day, “On that day many will say to me, ‘Lord, Lord, did we not prophesy in your name, and cast out demons in your name, and do many mighty works in your name?’ And then will I declare to them, ‘I never knew you; depart from me, you workers of lawlessness.’” Our omniscient Lord knows all, so when Jesus said "I never knew you,” He meant “know” in a relational sense. Jesus has no relationship with those who merely claim to be working in His name but who do not have a saving faith in Him.
When we love God, we are known by Him. In Mark 12:29–30, responding to a scribe’s question, Jesus presents love as the greatest commandment: “The most important is, ‘Hear, O Israel: The Lord our God, the Lord is one. And you shall love the Lord your God with all your heart and with all your soul and with all your mind and with all your strength.” Loving the Lord means knowing and obeying Him. Those who love the Lord will never hear the words “I never knew you” (Matthew 7:23).
In Romans 8:1, Paul asserts, “There is therefore now no condemnation for those who are in Christ Jesus.” Those who walk “according to the Spirit” are true children of God. Regardless of how many good deeds we do, our deeds do not save us. God, who reads hearts, truly “knows” His children.

implications for today

In the competitive career world, job seekers often hear “It’s who you know.” That’s bad news for those who don’t have connections; they probably won’t get the job even if they’re qualified for it. In an immeasurably more positive way, in Christianity, it’s also Who you know—as long as Who you know is Jesus as Lord and Savior. Our entry into heaven isn’t based on our qualifications either (Thank God! We’d never make it). But what does “knowing Jesus” look like in our lives? To start, it’s on a different plane than “knowing” a friend of a friend at the job you’re applying to. A big difference is the awareness that Jesus knows us. We can’t hide our flaws behind a polished professional profile. Our omniscient Creator reads the intent of our hearts. Mercifully, we can come before Him to confess our sins—including those of our hearts—and Our Heavenly Father will welcome us into relationship with Him. Prayer, confession of sin, daily Bible reading, and fellowship with other believers—those are some of the ways Christians can come to know the One who already knows us. Those who love the Lord will not have to hear Him say on judgment day, “‘I never knew you; depart from me, you workers of lawlessness” (Matthew 7:22–23).

understand

Jesus’ statement “I never knew you” refers to those without genuine saving faith despite outward religious acts.
God desires true love and obedience, not empty rituals or appearances.
True believers are known by Jesus and are secure in their salvation.

reflect

How can you ensure your faith goes beyond outward actions to reflect genuine love for God?
How do you evaluate whether your heart is aligned with God’s heart and will as opposed to just going through the motions?
How do you cultivate a deeper relationship with Jesus so that He truly knows you?

engage

How can we encourage others to prioritize genuine faith over appearances in their spiritual walk?
What steps can we take to guard against spiritual hypocrisy and instead focus on heart transformation?
How does understanding that Jesus knows our hearts influence how we approach worship, prayer, and service?