In The God of the Towel Jim McGuiggan writes:

In 490 B.C. as Xerxes was advancing into Greece, he came to Thermopylae, a small pass in central Greece. Herodotus tells us that by the time he got there, he had something like six million troops on land and sea. Gathered there to stop the advance of the powerful Persian monarch was a mere handful of Greeks headed up by 300 Spartans led by the Spartan king Leonidas.

When Persian troops came to check the pass, they saw 300 warriors brushing their long hair and doing calisthenics and other such things. Back they went to their master to report that some fools with weapons were playing games in the ravine. Demaratus, a Greek physician and counselor to the Persian court, assured the king they weren't playing games—they were performing a death ritual.

These men had come to die!

Many an unmarried man had volunteered, but Leonidas insisted on taking with him men who had living sons. They never meant to come back!

Love of Sparta motivated these men—love of humanity moved this God of ours. This God came to earth to die! In doing this, God was demonstrating his own love for us.