Christ has redeemed us from the curse of the law, having become a curse for us.
For it is written, “Cursed is everyone who hangs on a tree.”
"When we hear that Christ was made a curse for us, let us believe it with joy and assurance. By faith Christ changes places with us. He gets our sins, we get His holiness. By faith alone can we become righteous, for faith invests us with the sinlessness of Christ. The more fully we believe this, the fuller will be our joy. If you believe that sin, death, and the curse are void, why, they are null, zero. Whenever sin and death make you nervous, write it down as an illusion of the devil. There is no sin now, no curse, no death, no devil because Christ has done away with them. This fact is sure. There is nothing wrong with the fact. The defect lies in our lack of faith. . . . If I examine myself, I find enough unholiness to shock me. But when I look at Christ in me, I find that I am altogether holy."
--Martin Luther, Commentary on Galatians, 1535, Gal. 3:13