Ephesians 5:1-6

Therefore be imitators of God, as beloved children. And walk in love, as Christ loved us and gave himself up for us, a fragrant offering and sacrifice to God.
But sexual immorality and all impurity or covetousness must not even be named among you, as is proper among saints. Let there be no filthiness nor foolish talk nor crude joking, which are out of place, but instead let there be thanksgiving. For you may be sure of this, that everyone who is sexually immoral or impure, or who is covetous (that is, an idolater), has no inheritance in the kingdom of Christ and God. Let no one deceive you with empty words, for because of these things the wrath of God comes upon the sons of disobedience.

-Ephesians 5:1-6

In light of Paul's instruction to be imitators of God and to walk in love, his readers are warned about "sexual immorality and all impurity or covetousness".  They are also warned about filthiness, foolish talk or crude joking.  All these things are not to be found in the life of an imitator of God.  Instead of having these things in your life or doing such things, one is to instead be a doer of thanksgiving.  Thankfulness is to replace sexual immorality and crude joking.  Paul makes his point very clear by stating that those who are sexually immoral or impure or covetous are also those who have no inheritance in the kingdom of Christ and God.  These people should not expect to "go to heaven", though many hold this belief.  People may live avoiding sexual immorality, but be covetous and believe he or she is still going to heaven.  Someone may even say at their funeral, "she was a good person and she's in heaven now".  The truth is that no one is righteous.  If that's the case, who can be saved?  You should already know that it is only by grace through faith in Jesus Christ.  Then, what's the point of Paul warning his readers about these sins.  I think that Paul is warning people not to continue in sin.  Being an imitator of God and walking in love means to do away with foolish talk.  In fact, it seems as if there were some leading people astray with this false belief.  Paul, telling us about imitating God and walking in love, warns his readers against these sins, then warns against deceivers.  These deceivers are probably those promoting the idea that you can be an imitator of God and still walk in sin.  This is very dangerous and something Christians needs to beware.

Now, this is something you and I need to take very seriously.  I think it's easy for me personally to just think I'm above this and know this already.  Perhaps it's at that very moment that I am ensnared by such a dangerous trap.  Pride could take over or perhaps I could get lazy and think I'm impervious to these sins.  No, I need to flee from them and keep my eyes fixed on Christ.  He is best and is the one who fills all in all.