system
Given the following post, respond as if you're commenting on Reddit:
human
[LoTR] What exactly made Frodo so qualified to bear the Ring? Sam says, "I can't carry it for you, but I can carry you." Why can't he carry it?
gpt
To some extent that was purely loyalty to Frodo.  Sam knew that carrying the Ring was Frodo's responsibility and had no desire to usurp that.  He carried the Ring, and Sting when it comes right down to it, for as long as he did only because Frodo could not.  Once they could be returned he did so, because they weren't his to carry.  Sam resisted the Ring's influence when it tried to convince him to claim it and when it tried to convince him to steal it from Frodo, his ability to fight the Ring's corruption was never in question.  But part of that resistance was Sam's inherent loyalty to Frodo and his unwillingness to take the Ring.  Frodo carried the Ring mainly because it was passed to him from Bilbo, that alone qualified him.  

Frodo alone, of all the Ring's bearers, never stole it or had to take it from someone else, it was given to him.  Bilbo and Sam were the only ones to ever willingly surrender it.  Had Sam not been the sort to give it up of his own free will he would not have been worthy to carry it on.