19Now the works of the flesh are manifest, which are
these; Adultery, fornication, uncleanness, lasciviousness,
20Idolatry, witchcraft, hatred, variance, emulations, wrath, strife, seditions, heresies,
21Envyings, murders, drunkenness, revellings, and such like: of the
which I tell you before, as I have also told you in time past, that they which do such things shall not inherit the kingdom of God.
22But the fruit of the Spirit is love, joy, peace, longsuffering, gentleness, goodness, faith,
23Meekness, temperance: against such there is no law.
24And they that are Christ's have crucified the flesh with the affections and lusts.
So it is saying that if you keep doing those things you will not inherit the kingdom of God. Even if you claim to believe in Jesus but you keep on doing those things then you will not inherit the Kingdom of God.
David did not keep doing those things. He repented and quit doing those things.
Christians used to do those things and they were born again and were forgiven and washed by the blood of Christ and no longer do those things.
However, if someone listens to a slick tongued trickster who bends scriptures about the grace of God and they think that they can keep on doing those things and still go to heaven because they can't loose their salvation so they become a drunkard again and stay that way they will not inherit the kingdom of God.
Here is another passage where the same author Paul said something similar and adds a bit more to give you more understanding.
1 Cor 6:9
9Know ye not that the unrighteous shall not inherit the kingdom of God? Be not deceived: neither fornicators, nor idolaters, nor adulterers, nor effeminate, nor abusers of themselves with mankind,
10Nor thieves, nor covetous, nor drunkards, nor revilers, nor extortioners, shall inherit the kingdom of God.
11And such were some of you: but ye are washed, but ye are sanctified, but ye are justified in the name of the Lord Jesus, and by the Spirit of our God.
So you see that these Corinthians had been guilty of such sins in the past but they were washed, and sanctified, (which means they were changed by the Spirit of God to live differently) They no longer did those things.
And yet he warns them and he warns us today. BE NOT DECEIVED.. if you continue doing these things after you have been washed because you heard a teaching that you can go to heaven anyway BE NOT DECEIVED.. because there were false teachings at the time that Paul wrote this that were telling Christians that they could sin with their flesh nature and their spirits were innocent and they would still go to heaven because the flesh is nothing.
BE NOT DEVCEIVED because there are people being influenced by the same demons that were teaching in Paul's day (demons don't die) and they are still trying to convince people that they can do all sorts of sins like being a drunkard and still go to heaven. But BE NOT DECEIVED they that
practice such things will not inherit the Kingdom of Heaven no matter how many times they pontificate about seals and mason jars, and nobody being able to pluck them out of Gods hand, and sons are always sons, and once saved always saved, and pass my my salt shaker and lime and glug glug glug, and if I am sleeping with my girlfriend it is ok because God knows our hearts and I can't loose my salvation nonsense. BE NOT DECEIVED. They that practice these things will not inherit the kingdom of heaven.