"For of this you can be sure: No immoral, impure or greedy person - such a man is an idolater - has any inheritance in the kingdom of Christ and of God." NIV translation
This verse causes some confusion as many take it to mean that, if you do these things, you go to hell. That's not what it is saying as we all sin even after we are saved. But, if these things are a normal part of your life and you are comfortable with that, then you need to ask yourself about your own salvation. The Holy Spirit living in the believer convicts us of sins and calls us to repent. If we ignore that and don't repent, we will be troubled in our minds instead of comfortable in sin. Paul says those that are doing this and comfortable in it are idolaters meaning they have put this activity above the Word of God and worship it more than God.
Those who engage in the sins described will face God's wrath and judgment. Not only are we not to do those things but we are not to associate with them as they participate in them.
We can tell them about Jesus and how to be delivered out of sin but, when they go to do those things, we are to separate ourselves.
"For you were once darkness, but now you are light in the Lord. Live as children of light" NIV translation
It is interesting to note that Paul tells the Ephesians believers that they "were once darkness" and not that they were in darkness. That may seem like a small point but it is crucial to understand our relationship with Jesus. Before we were cleansed of our sins by the blood of Jesus Christ, we focused on the things of this world and left God out of our daily lives. Without God, there is no light because God is light and in Him there is no darkness. Therefore, we were darkness but, when we accept His gift of grace, God gives us a piece of Himself to live in us (the Holy Spirit). Then, with God living in us, we are light and we should live like what we are.
"(for the fruit of the light consists in all goodness, righteousness and truth) and find out what pleases the Lord." NIV translation
Fruit is naturally produced by a tree when it has plenty of water and light. Likewise, when we are children of God, fruit should be produced as we study His Word to find out what pleases Him. The water for our tree is the very Word of God and God Himself is our light as He lives in us through the Holy Spirit. That fruit will be that we seek to do the right thing as defined by God's Word in every part of our lives and at all times. We not only read and study the Word but we also will put it into action as children of God.