In Galatians 3:10, Paul tries to explain to the Galatian church the long-lasting of effects of trying to live “under the law”. What is the outcome of trying to earn God’s love, as opposed to having it given to you in Christ? Paul says, “for all who rely on works of the law are under a curse”. Now, what does Paul mean by this?
Tim Keller, in his Galatians commentary “Galatians for You”, explains:
The result of living by the law is that we are “under a curse” (v. 10). This “curse” has two aspects. Theologically, anyone who says: I can be saved by obeying the law must then be prepared to really look at what the law commands. To love God wholly, we would have to obey the law wholly. To be blessed by God instead of cursed by Him, we would have to look at the law and satisfy its every demand. And that cannot be done. Objectively, attempting salvation-by-law-observance means we are cursed.
This means that, psychologically, everyone who is seeking to save themselves by their performance will experience a curse subjectively. At the very least, attempting to be saved by works will lead to profound anxiety and insecurity, because you can never be sure that you are living up to your standards sufficiently, whatever they may be. This makes you over-sensitive to criticism, envious and intimidated by others who outshine you. It makes you nervous and timid (because you are unsure of where you stand) or else swaggering and boastful (because you are trying to convince yourself of where you stand). Either way, you live with a sense of curse and condemnation.