Do you think that sometimes Christians use the "we don't really know their hearts" as a way to excuse their behavior? [Matthew 12:34, Luke 6:45, Mark 7:21, Matthew 7:17-18, Romans 7:23, Matthew 18:17].
If we are going to give account of every evil word we speak, are not the evil words covered under the blood of Jesus? [Matthew 12:34-36, 1 Corinthians 11:31, 1 John 1:7-9].
Is this a correct way to view the passage about "I never knew you" to think these are false prophers or those that have rejected Him? [Matthew 7:21-22, Matthew 12:33-37].