David Grann has penned a gripping New Yorker profile on Arctic explorer Henry Worsley. If you don’t have time to read the whole lengthy piece (or even if you do), this 25 minute New Yorker Radio podcast is a fantastic supplement. A retired British army commando, he was obsessed with the Arctic explorer (and current leadership book icon) Earnest Shackleton. Worsley (who once spent the night sleeping near his hero’s grave) adopted Shackleton’s credo as is own: “by endurance we conquer.”

Shackleton’s fame, however, should not obscure the fact that he was “in many ways, a failure.” He emerged physically broken after Captain Robert Scott’s 1902 retreat from his polar expedition. In 1906, Shackleton led his own valiant yet unsuccessful journey toward the South Pole, eventually ordering a retreat to save the lives of his men. While Shackleton was reticent to talk about his failure with his wife Emily, he did ask her, “A live donkey is better than a dead lion, isn’t it?”

After leading successful expeditions with others in 2008 and 2011, Outside magazine called Worsley “one of the great polar explorers of our time.” But Worsley’s obsession with endurance pushed him beyond his previous milestones. He had internalized a line from a James Elroy Flecker poem: “always a little further…a little further.” And so, at the age of 55, Worsley set off for what he hoped would be an 80-day solo journey. He endured temps of minus-40 degrees Fahrenheit, was often disoriented, windblown, dodging deadly crevasses, all the while pulling a sled nearly double his own weight. After covering over 900 miles in a little over two months, Worsley’s body became battered by various illnesses, dehydration, and sheer exhaustion. Just 30 miles from his goal, a defeated Worsley radioed for an airlift. Sadly, his body was by then too far gone, and he passed away from organ failure before his wife Joanna could see him.

It is easy to lionize Worsley, who strikes me as a wonderful guy and near superhuman in his physical and mental discipline.

Still, Grann writes:

In his diary, he [Worsley] had written, “Never, ever give in.” It echoed a lesson from one of the Shackleton self-help books, which Worsley had once posted on his Web site: “Never give up—there’s always another move.”

But maybe that was wrong. Hadn’t Shackleton survived because he had realized that, at a certain point, he had no more moves and turned back? Unlike Scott and others who went to a polar grave, Shackleton reckoned with his own limitations and those of his men. He understood that not everything, least of all the Antarctic, can be conquered. And that within defeat there can still be triumph—the triumph of survival itself.

As I said, I stand a bit in awe of Worsley, but still view him with greater sadness. Endurance is a demanding god, and ultimately will break us all (especially when we insist on attempting to endure alone). Even the strongest among us can end up like the Old Testament prophet Elijah, collapsed under his juniper tree, ready for the Lord to take him home.

But maybe the real key is not “always a little further.” Maybe it is rather a messenger of grace, intervening, and reminding us that “the journey is too much for you” (1 Kings 19:7). And endurance, as admirable a biblical virtue as we can hope for, is ultimately not our conqueror. Christ himself took care of that, a dead lion (of Judah) who took the place of living donkeys like me.