Being 'known by Jesus' in Matthew 7:22 In Matthew 7:21-22 Jesus says for Him to know me I must do His will. There are plenty of scriptures that talk about God seeing us and knowing us, why then does Jesus say I didn't know you? Is it because the word 'know' is more of an intimate 'knowing' ie, a relationship?
For Jesus to ‘know’ us means we have submitted to his Lordship and we are no longer slaves but are intimate acquaintances.  Jesus said this of his disciples: 


  Whoever does God’s will is my brother and sister and mother (Mark 3:35).


When we know Jesus and believe in him, we are adopted into God’s family:


  Yet to all who received him, to those who believed in his name, he gave the right to become children of God (John 1:12)  


We can call God “Abba, Father” (Romans 8:15).  It doesn’t get more personal and intimate than that!  When people speak of “knowing” Jesus, they refer to having a relationship with Him.  Being a Christian is more than knowing about Jesus; being a Christian is about knowing Him personally.  Jesus spoke of the need to know the Saviour when He prayed:


  This is eternal life: that they know you, the only true God, and Jesus Christ, whom you have sent” (John 17:3).  


When we know Jesus, we also know God:


  We know also that the Son of God has come and has given us understanding, so that we may know him who is true.  And we are in him who is true – even in his son, Jesus Christ.  He is the true God and eternal life. (1 John 5:20)


There were people in Jesus’ day who thought they were friends of his because they knew the Law, made strict rules for themselves (and for others), and listened to his teaching.  They followed him, applauded the miracles, and liked some of what he said. But Jesus calls them “evildoers” and declared, “I never knew you.”  Matthew 7:21-23

They didn’t know who Jesus REALLY was.  Some people have an intellectual, head knowledge of Jesus.  They may have read the Bible and believe it, but have never allowed the truth about Jesus to penetrate into their hearts so that their lives are transformed.  Jesus said:


  These people honour me with their lips, but their hearts are far from me. They worship me in vain; their teachings are but rules taught by men. (Matthew 15:8–9 quoting Isaiah 29:13)


To really know Jesus means we grasp the significance of what God, in Jesus, did to pay for our sins and we seek his forgiveness so that we may know him personally, and enjoy intimate fellowship with him through the Holy Spirit (Acts 2:38).