Actually the crowd in the passage of which you speak are charismatics since they are the ones that think casting out devils, and doing miracles is a good thing and they are the false converts Jesus explicitly spells out here. Unless you know of a Calvinist that believes in doing miracles and casting out devils. Do you?
Oh, I agree, but those folks who say "Lord, Lord" are Lordship Salvation folks all the way.
What is important is that this passage shows you can believe in Jesus as Lord and not be saved. Why? Because these persons "trusted in themselves" as is also shown in Luke 18.
Luk 18:9 And he spake this parable unto certain
which trusted in themselves that they were righteous, and despised others:
10 Two men went up into the temple to pray; the one a Pharisee, and the other a publican.
11 The Pharisee stood and prayed thus with himself, God, I thank thee, that I am not as other men are, extortioners, unjust, adulterers, or even as this publican.
12 I fast twice in the week, I give tithes of all that I possess.
13 And the publican, standing afar off, would not lift up so much as his eyes unto heaven, but smote upon his breast, saying, God be merciful to me a sinner.
14 I tell you, this man went down to his house justified rather than the other: for every one that exalteth himself shall be abased; and he that humbleth himself shall be exalted.
Was the Pharisee an atheist? NO, he believed in God. Was God "Lord" to the Pharisee? Yes, Pharisees were very obedient, Paul said of the law that he was "blameless".
Phi 3:6 Concerning zeal, persecuting the church;
touching the righteousness which is in the law, blameless.
Were Pharisees obedient? YES, remarkably so. We often criticize the Pharisees, but in reality they were very devout and obedient to the law. The problem is they trusted in themselves that they were righteous, just as those false converts in Matthew 7 did.
Note how this Pharisee boasted of all his good works just like the lost persons in Matthew 7.
But the publican was very different. He made no boast whatsoever of being obedient or righteous. He confessed he was nothing but a sinner and cast himself completely on God's mercy. And he was saved.
This is saving faith, to place your complete dependence and trust upon Jesus Christ alone and his mercy to save you.
And folks can get all mad if they want to, but all this man did was pray a simple prayer and ask God to forgive him.
And God did forgive him.
Jesus did not tell us these parables without reason. Learn from them what is true doctrine and what is not.