I believe there are people inside the church today who will be outside the gates of Heaven. Being in a church does not mean you are getting into Heaven. We, as individuals, must put our faith in Jesus Christ because one day we will stand before God all by ourselves.
Heaven is not the default destination of every person. It is promised only to those who have believed in Jesus Christ. We have this warning in Revelation 21:8: "But the cowardly, unbelieving, abominable, murderers, sexually immoral, sorcerers, idolaters, and all liars shall have their part in the lake which burns with fire and brimstone, which is the second death."
It takes courage to be a Christian. People will harass you and make fun of you. You may even be physically harmed. Some have lost their lives because they believed in Jesus. It takes courage to make your stand for Christ, especially in our culture today.
The cowardly won't make it into Heaven. Some are afraid of what others think, which I have always found amazing. I don't think we would be as concerned about what others think of us if we realized how rarely they do. If you are cowardly, meaning that you won't stand up and follow Jesus, then you won't have any value system. You won't have any absolutes. You will pretty much do what you want.
That leads to being abominable—being wholly caught up in wickedness and evil, pulling out all the stops and removing all restraints. It is going whole hog into evil.
Revelation 21:8 is a warning that we need to heed. Some people may say, "Well, I don't agree with that."
God makes the rules, and we can either follow them or reject them. But it is not for us to edit God.