Answer
The fact that Adam and Eve had a choice to make in the Garden of Eden shows beyond all doubt that mankind was created with a free will. The first couple chose to sin, and that choice has plunged the entire world into spiritual darkness leading to our need of salvation. Through it all, mankind has retained his free will, and we will retain free will in heaven. Is it possible that people in heaven can exercise their free will to sin again and get kicked out of heaven? No, it is not possible.
To back up a bit, we need an acceptable definition of free will. We have free will, but not in the way most people think. Our freedom consists in the fact that we are free to choose according to our desires. As long as we have a minimum of two available options, we must make a choice, and we will always do so according to our strongest desire. But, in the case of a fallen sinner, he or she is not at liberty to choose according to righteousness. This is what Jesus means when He says that the one who sins “is a slave to sin” (John 8:34). This is not the language of “free will” as people typically think of it. The unregenerate person has a sinful nature; he is not just inclined to sin but driven by sinful impulses. It is perhaps helpful to say, “We are free to choose what we want but not free to want what we ought.” This greatly limits our “freedom” because the list of things we want (as sinners) coincides with whatever pleases our sinful impulses. Our choices are for things that will ultimately destroy us (Proverbs 14:12). As Paul says, “Oh, what a miserable person I am! Who will free me from this life that is dominated by sin and death?” (Romans 7:24, NLT).
When we are saved, we are liberated from our natural bondage to sin. The Holy Spirit sovereignly regenerates us and in grace gives us the ability to want what we ought to want, namely, forgiveness, salvation, and the lordship of Christ. When we trust in Jesus for salvation, we begin a moral progression, a journey toward holiness in which we put to death daily the sinful impulses that reside within us and strive toward godliness. In heaven we will be completely devoid of sin; our only desires will be for the things of God—things that bless us, fulfill us, and give us life. This is true liberty (see Romans 8:21). We will retain our free will in heaven, but our will is sanctified there. The sin nature will be gone.
In heaven we are completely conformed to the image of Christ (Romans 8:28–30). Our sanctification will be finished; we will not even want to sin. Also, in heaven there is no temptation to lure us and no devil to deceive us. Unlike Adam and Eve, we will face no test; our moral state will be secure. No one will get kicked out of heaven. Just as our Lord Jesus has a truly free will yet is without sin, so will we retain a free will yet be without sin. We will be like Him (1 John 3:2).
Before salvation, our free will on earth is limited by our inability to choose what is right. After salvation, our free will struggles between choosing what is right and what is wrong. In heaven our free will is limited by our inability to choose what is wrong. In our glorified state, we will exercise our free will to choose what is true, noble, right, pure, lovely, and admirable (see Philippians 4:8).