What does Matthew 7:21 mean?
This verse is deeply challenging, and the subject of many debates. Scripture is clear that salvation is entirely by grace through faith, and not earned by good deeds (Titus 3:5; Galatians 2:16; Romans 11:6; John 6:28–29). The Bible also strongly reminds believers that all people—even those who are born again—have sin which needs to be addressed (1 John 1:9–10; Hebrews 4:14–16). However, God's Word also indicates that those who are truly born again will see that salvation reflected in their attitudes and actions (James 2:14–17; John 14:15). A similar tension exists in this passage—emphasizing that Christ, not deeds, is what saves (John 14:6), and yet submission to Christ is an expected result of salvation (Luke 6:46).While this verse is commonly mis-applied by those who claim that good works are required to be saved, the very next statement Jesus makes destroys that interpretation. In fact, those who primarily define their faith by what they've done for God have placed their faith in something other than Christ (Matthew 7:22–23). In these few verses, Jesus explicitly explains that to do the will of God means something more than mere action—it requires genuine faith.
Having warned His listeners to beware of false prophets, Jesus made it clear that it's possible for other people to "put on" a show of faith and fool us. Christians should be aware of false leaders, and other people who claim to represent God when they do not (Matthew 7:15–20). Here, He offers the other side of this two-part alert: beware of false followers. Specifically, Christ is warning those who hear Him not to fool themselves into thinking they are true believers, when in fact they are not.
Jesus declares that not everyone who refers to Him as "Lord" will enter the kingdom of heaven. The title of "Lord" implies a master, a leader, and someone to whom the speaker submits. In prior teaching, Jesus indicated that mere words and actions are not enough—they must be motivated by sincerity and truth (Matthew 6:1, 5, 16). In that same way, Jesus states in no uncertain terms that merely referring to Him as Lord is not enough. Neither are acts of supposed righteousness. Entrance to the kingdom of heaven is limited to those who truly, fully do the will of His Father in heaven (2 Corinthians 13:5). That starts with sincere faith in Christ (John 6:28–29) and extends to humility in how we live our lives (John 14:15).
For the first time in this sermon, Jesus refers to God as "my Father." Jesus Himself did the will of His Father in heaven. Those who truly follow Him will do the same.
Both John the Baptist and Jesus taught that Jesus' arrival on earth meant that the kingdom of heaven was near (Matthew 3:1–2; 4:17). This is Christ's eternal kingdom, which will begin in the hearts of all who are truly His (Jeremiah 31:31–33; Hebrews 8:6–7). This will eventually become a true and political kingdom where God's will is done on earth as it is in heaven (Revelation 20:4–6). Only those who come to the Father through true faith in Christ will become citizens of that kingdom forever.