It is true that sinners will go to heaven, but only converted sinners. There are a lot of very bad people who will be in heaven someday because they recognized their sins, believed in Jesus Christ, and were changed by the power of the Holy Spirit. But those who continue to do and enjoy their sins and prefer disobedience over obedience to God have no relationship with God and are destined for hell:
Do not be deceived: Neither the sexually immoral nor idolaters nor adulterers nor men who have sex with men[a] 10 nor thieves nor the greedy nor drunkards nor slanderers nor swindlers will inherit the kingdom of God. (I Corinthians 6:9-10 NIV)
Here are a list of people who will not go to heaven if they continue in their sins without repenting.
The Sexually immoral will not go to heaven. Any one commits adultery and repents may be saved, but those who commit adultery and continue doing it, or do not regret doing, are absolutely not God’s children, because they prefer to exercise lust over true love.
Idolaters are not going to heaven either. And idolater is someone who does not make God the highest priority of his life. Instead he worships something, a false God, a career, or a lifestyle, more than he worships God.
Homosexuals will not go to heaven either unless they repent. This does not mean that everyone who struggles with homosexual lusts will go to hell, anymore than those of us who struggle with heterosexual lusts will go to hell. But if someone is consistently having sex with a person of the same gender they are not even trying to obey God’s commandments. They are simply choosing their own lifestyle over what God has said is right.
Unrepentant thieves will not go to heaven either: those who take what is not theirs, and love doing it. Drunkards, are in this same group: those who purposefully allow themselves to be intoxicated time and time again, knowing a head of time the damage that they will cause to others. Slanderers, who delight in spreading negative comments simply to hurt people are also not Christians, unless they repent of their slander and are washed in the blood of Christ. Swindlers, people who use their personality and influence to get other people to give them things that they really don’t want to give away, also belong in this group. They are not children of God either.