“For while we were still weak, at the right time Christ died for the ungodly. For one will scarcely die for a righteous person—though perhaps for a good person one would dare even to die—but God shows his love for us in that while we were still sinners, Christ died for us” (Romans 5:6–8 ESV).
“The measure of God’s love for us is shown by two things. One is the degree of his sacrifice in saving us from the penalty of our sin. The other is the degree of unworthiness that we had when he saved us… When we add to this consideration the horrific death by crucifixion that Christ endured, it becomes clear that the sacrifice the Father and the Son made was indescribably great—even infinite, when you consider the distance between the divine and the human”
(John Piper, Fifty Reasons Why Jesus Came to Die [Wheaton: Crossway, 2006] p. 28-9).
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.