Of course St Paul does not refer in this verse to things which violate the moral law of God, but rather to things which, while lawful, may not be helpful. For it sometimes follows that was is fine for others causes harm to me. A glass of wine is good, but not for an alcoholic. A few potato chips are tasty and good, but some struggle to eat them in moderation and should stay away. Others struggle with salt or or sugar, both gifts of God but not helpful for those with hypertension or diabetes. I love peanut butter, but I cannot eat it in moderation so I don’t eat it at all. Making extensive travels may be fun and enriching, but not perhaps for someone who has duties to stay close to home and care for children.
Learning that all things are not helpful or expedient is a wisdom that saves us a lot of trouble.
Let us be clear again, this this does not refer to transgressions of the moral law. St Paul is not saying unchastity, or wrathful anger, or greed etc are “lawful” and thus above criticism. These sorts of things ought be critiqued and corrected along with a call to repent.
But even for lawful pleasures, a certain care is necessary. And thus Paul speaks of accepting that not all available pleasures are for us, or to be indulged just because we want them. Other factors such as health, safety, charity toward others, cost, the relationship of some pleasure to other duties, etc are all factors that may make a lawful pleasure inexpedient.
I thought of all this when I saw this video. It features a youngster with a strange horn protruding from his head. Perhaps it is a devilish horn of some sin or addiction. At any rate he sees others eating ice cream and seeks some for himself. But the ice cream man warns him that this pleasure is not for him for some unknown reason related to the horn. This pleasure is lawful, but for him it is not expedient.
But the youngster has a melt down, a temper tantrum and the ice cream man relents. As you will see in the video, the youngster suffers the effects. For, as St. Paul says, “All things are lawful for me, but not all things are expedient.”