At the judgement, many will protest that they deserve entrance into Heaven. Despite their protests, Jesus will emphatically deny that He ever knew them.* They never had a personal relationship with Him through repentance and faith and trust in Him. Jesus will then command them to depart from Him and send them to Hell forever! (See: Hell Was Not Made for Humans - One Way Jesus.)
They will weep and grind their teeth in anger! (See: What does the Bible mean when it refers to the gnashing of teeth? - GotQuestions) They never took the time to know Jesus as Savior while they were here on this earth and now it will be too late! (See: What does it mean that today is the day of salvation? - GotQuestions). Consequently, they will live forever in agony and torment knowing nothing but the judgement and wrath of God!
[F]or many, I say to you, will seek to enter and will not be able. 25 When once the Master of the house has risen up and shut the door, and you begin to stand outside and knock at the door, saying, ‘Lord, Lord, open for us,’ and He will answer and say to you, ‘I do not know you, where you are from,’ 26 then you will begin to say, ‘We ate and drank in Your presence, and You taught in our streets.’ 27 But He will say, ‘I tell you I do not know you, where you are from. Depart from Me, all you workers of iniquity.’ 28 There will be weeping and gnashing of teeth, when you see Abraham and Isaac and Jacob and all the prophets in the kingdom of God, and yourselves thrust out. - Luke 13:24b-28 NKJV
*Paraphrased from The John MacArthur Study Bible
Saving Faith vs. Intellectual Assent - One Way Jesus
We All Need The Gospel, Especially The Falsely Assured - Christian Research Network
What did Jesus mean when He said “I am the door”? - GotQuestions
I Am the Door (John 10:1–10) - John MacArthur
The Ark is a Picture of Salvation - One Way Jesus