I would like to jump in and comment on the Matt 7:21 passage.
Earlier in Matt 7:7, Jesus says, "Ask, and it will be given to you; seek, and you will find; knock, and it will be opened to you. 8For everyone who asks receives, and the one who seeks finds, and to the one who knocks it will be opened.
Then he says in verse 13-14, “Enter by the narrow gate. For the gate is wide and the way is easy that leads to destruction, and those who enter by it are many. 14For the gate is narrow and the way is hard that leads to life, and those who find it are few.”
He talks about the broad gate that leads to destruction and it takes some seeking to find the narrow way, and only a few find it. Most people are lost.
Then he warns about false teachers. Do false teachers know they are false teachers? I think that the vast majority do not know they are false teachers. In fact, in Luke 6:39 which is either the same as the sermon on the mount or covers much of the same material, Jesus said, “He also told them a parable: "Can a blind man lead a blind man? Will they not both fall into a pit?”.
Then Jesus makes the statement starting in verse 21, “Not everyone who says to me, 'Lord, Lord,' will enter the kingdom of heaven, but the one who does the will of my Father who is in heaven. 22On 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?' 23And then will I declare to them, 'I never knew you; depart from me, you workers of lawlessness.”
These people were obviously sincere; else they would not be arguing their outcome. They were on the broad way when they thought they were on the narrow way. They believed in Jesus and worked for him their whole life, yet they were lost. They were not doing the will of the Father. Isn’t it God’s will to preach and do good works in His name? It must matter what we teach. It has to be more than Jesus is Lord, because that is what these people believed. Notice, Jesus did not say, “I once knew you but now I don’t”. He said, “I never knew you”. These people were never on the narrow way. They were blindly led down the broad way into destruction.
Then he gives the story of the wise and foolish men, one who hears and does, the other hears, but does it his own way. Both were diligent in building homes. Why would anyone build a home with the realization that it would fall down. They wouldn’t. Why would anyone devote their lives to Jesus with the realization that the end was destruction? They wouldn’t.
Jesus asked a simple question, in possibly a parallel passage, in Luke 6:46, "Why do you call me 'Lord, Lord,' and not do what I tell you?”.
Some people will say, Just accept Jesus as your Lord and Savior and that’s all it takes. Once you are saved, there is nothing you can do to be lost. Wow, that sure sounds like a broad way to me. Those in verse 21 of Matt should be saved because they called him Lord. They believed in Him and worked their entire lives for Him.
Jesus also said, “Go into all the world and proclaim the gospel to the whole creation. Whoever believes and is baptized will be saved, but whoever does not believe will be condemned.” – Mark 16:15-16. People come up with a whole hosts of reasons as to why this doesn’t really mean what it says, when it is so simple it requires help to misunderstand it. I cannot but think Jesus would say the same thing today as he said some 2000 years ago, “Why do you call me ‘Lord, Lord,’ and do not do what I tell you? What more effective weapon would Satan have in his arsenal than to convince people that Jesus didn’t really mean what he said and that baptism was unessential and unnecessary, all you have to do is believe and you are always saved. Notice, in Matt 7, Jesus said MANY would come to him in that day. Not a few, not some, but MANY. Many are on the broad way, calling Jesus Lord, working for him, yet bound for destruction, because they never knew him. How sad.
In the first century, preaching Jesus included instructions for water baptism (Acts 8:35-36). The gospel is the death, burial and resurrection of Jesus (I Cor 15:1-4). We obey a form of that in our water baptism (Rom 6:3-4, 17). Preaching Jesus today is no different than it was 2000 years ago. If we preach another gospel, we are to accursed (Gal 1:8-9). The Galatians changed the gospel by adding to it. If we add to or subtract from, we no longer have the gospel. The broad way is filled with many "gospels", yet there is just one faith, one Gospel, and we are to be all speaking the same thing (Eph 4:5, Gal 1:7, I Cor 1:10)
Let's all ask, seek, and knock to find the narrow way that leads to life. Let's not just call Jesus Lord, but do what he says.