Reunited, Frodo and Sam set out into the desolation of Mordor, to cross the long miles to Mount Doom.
It is a very long way, and very hard going. There's nothing to eat in the bleak landscape, and no safe water to drink. Checking their supplies Sam makes the calculation. They only have enough food and water to make it to Mount Doom. There is not enough to make a return trip. If they get to Mount Doom, and somehow complete their mission, that will be their last and final act. Even if they succeed, they will die in the attempt.
Sam tried to guess the distances and to decide what way they ought to take. 'It looks every step of fifty miles," he muttered gloomily, staring at the threatening mountain, 'and that'll take a week, if it takes a day, with Mr. Frodo as he is.' He shook his head, and as he worked things out, slowly a new dark thought grew in his mind. Never for long had hope died in his staunch heart, and always until now he had taken some thought of their return. But the bitter truth came home to him at last: at best their provision would take them to their goal; and when the task was done, there they would come to an end, alone, houseless, foodless in the midst of a terrible desert. There would be no return.
'So that was the job I felt I had to do when I started,' thought Sam: 'to help Mr. Frodo to the last step and then die with him? Well, if that is the job then I must do it. But I would dearly like to see Bywater again, and Rosie Cotton and her brothers, and the Gaffer and Marigold and all...'
But even as hope died in Sam, or seemed to die, it was turned to a new strength. Sam’s plain hobbit-face grew stern, almost grim, as the will hardened in him, and he felt through all his limbs a thrill, as if he was turning into some creature of stone and steel that neither despair nor weariness nor endless barren miles could subdue.
The most well-known quote from Dietrich Bonhoeffer's The Cost of Discipleship is, "When Christ calls a man, he bids him come and die." That's what I think of when I stand with Sam in this moment. Sam realizes he's been called to die. That has been the mission all along.
And facing this, Sam commits to the path. Sam's dream of returning home dissolves, but it is transformed into a new strength. It reminds me of Jesus' words in the gospels, "No one who puts a hand to the plow and looks back is fit for service in the kingdom of God." It's a one-way ticket.
Life with God is an "all in" enterprise. You can't kinda, sorta walk the path to Golgotha. You either pick up the cross, or you don't. You can't kinda, sorta love someone unconditionally. You either love them, and all the sacrifice unconditional love entails, or you don't. Sam is either giving his life away to get Frodo to Mount Doom, or he's turning around.
All this is why our first movement toward God is described as a death, as total renunciation and surrender. Total loss. The strings cut. Every kinda, sorta, coulda, woulda, shoulda excuse laid to rest and buried. The cross lifted and set to the shoulder. In the words of St. Paul:
Indeed, I count everything as loss because of the surpassing worth of knowing Christ Jesus my Lord. For his sake I have suffered the loss of all things and count them as rubbish, in order that I may gain Christ.
