Who are the people who think being saved means they can do whatever they want?
They are people with a pseudo salvation, who may have tasted of salvation and had an emotional experience but never entered a genuine salvation experience. True believers know better than to use grace as an occasion to the flesh and claim they can do whatever they want.
Les explains that in Galatians 5:13, believers are not to use their liberty as an occasion to the flesh. He notes that some say, "Well, I'm now saved. I'm a child of God and I can do whatever I want to do." He thinks most true believers know better. Such people likely have a pseudo salvation; they may have tasted of it and had an emotional experience, but they never really entered into a genuine salvation experience. Those kind of people may take this approach, but for the true believer, most know better. Paul writes to the Galatian believers to use not liberty for an occasion to the flesh, but by love serve one another. This applies among believers, not necessarily the unbelieving world.