“For even the Son of Man came not to be served but to serve, and to give his life as a ransom for many” (Mark 10:45 ESV).
“…one of the reasons Jesus loved to call himself ‘the Son of Man’ (over sixty-five times in the Gospels) was that it had the ring of mortality about it. Men can die. That’s why he had to be one. The ransom could only be paid by the Son of Man, because the ransom was a life given up in death.”
(John Piper, Fifty Reasons Why Jesus Came to Die [Wheaton: Crossway, 2006] p. 35).
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.