Are you one of those people who insists that our free will is a gift from God? By your definition it would appear to be a curse.
Which is it?
Sin is the curse. Free will, at the beck and call of fallen, sinful creatures, plays itself out in ways that fall short of its intent and purpose.
God intention for us was that we would exercise free will in worshiping Him and enjoying Him forever. This is what will happen in heaven.
It can be either, and we are faced with that choice daily.
“Which is it?”
It’s a gift, just a gift with potentially bad consequences if misused.
For example, say I give you an automobile. Most would be thrilled with that gift. Yet, if you get drunk, drive it, and run someone over, you can turn the gift into a curse.
It is blessing, because whenever we choose to do right we glorify God.