This is false. You are taking things too far...as all religious people do. The judgment of Christ is about the kind of works you do. Are they eternal works prepared in advance? Are they just human works based on religious posturing. Many will be rejected by God.
Out of the same lump God makes vessels for honour and vessels of dishonour. Humble yourself in the fear of the Lord and pray that God would keep you in His mercy.
And learn that God has no favourite special people. He rejected His own people when their attitudes became too smug. Be careful because you sound too smug to me.
I agree. Some groups believe what they believe makes them saved no matter how they behave or at some later point believe.
To me this is a non-covenant based on a non-relationship. The prophets said simply the promises God gave to His people were based on them loving and appreciating Him and His commands and following Him. If they chose the way of the world, no matter what went before would be forgotten and as with Korah the ground would open up and swallow them whole.
Arrogance says, we are the chosen, secure in the promise, though we are rebellious evil wicked people who ignore and disobey the principles and heart of the King. And God replaced these people with the disciples, grafted into the vine, because they walked the way of love. It is impossible to be in Christ and not be in love and its dynamic life. It is like saying a marathon runner can turn up on the day of the marathon and run it without training and preparation. They will just fail, and only fools behave like this. No a marathon runner creates a training plan and follows it so when the day comes they are ready to achieve the race and end it. Jesus uses exactly the same language and Paul also.
And the cost is our lives, everything we are, to become a new creation, set in Christ that effects everything we do, say, think and desire.
It is hard to say anything that is actually left out. Put simply if the word of Christ dwells in your heart, these are the words Christ speaks to us.