All who rely on observing the law are under a curse, for it is written: “Cursed is everyone who does not continue to do everything written in the Book of the Law.”
When discussing heaven with people who are not Christians, almost everyone will respond that they expect to go to heaven if they believe in it. When they are asked why they expect to go to heaven, the response is almost always that they are a relatively good person who tries to live a good life.
We have no standard in scripture for “how good is good enough.” The only standard that we have is perfection and according to that standard, everyone falls short. No matter whether a person is relatively good or extremely good, they still don’t reach the required level of perfection. Little sins count just as much as big sins in comparison to perfection.
So everyone is cursed according to the law; from the very best to the most evil people alive. We just aren’t good enough to get into heaven on our own.
Fortunately Jesus did live a perfect life. And even though He didn’t deserve it, He took the curse for us. He took the penalty for us and paid the debt we couldn’t pay. We couldn’t be perfect so Jesus was for us.