“There is a holy curse hanging over all sin. Not to punish would be unjust. The demeaning of God would be endorsed. A lie would reign at the core of reality. Therefore, God says, ‘Cursed be everyone who does not abide by all things written in the Book of the Law, and do them’ (Galatians 3:10; Deuteronomy 27:26). But the love of God does not rest with the curse that hangs over all sinful humanity. He is not content to show wrath, no matter how holy it is. Therefore God sends his own Son to absorb his wrath and bear the curse for all who trust him. ‘Christ redeemed us from the curse of the law by becoming a curse for us’ (Galatians 3:13).”
(John Piper, Fifty Reasons Why Jesus Came to Die [Wheaton: Crossway, 2004] 21).
The rest of the above referenced book can be downloaded for free as a PDF. This book makes a great devotional for daily Lenten meditations.