Mark 9:41

Not sure if you still come here, but

There are some pretty interesting cultural factors that should inform our interpretation: Honor and shame, hospitality, patronage, group boundaries, and the way the earliest Christians thought about who was of greatest concern. I don't have time to discuss all of them so I'll leave some names at the end.

Here's the tl;dr
Jesus is say that those who show hospitality to the Jesus-group will be blessed. It is not a statement about "salvation" but rather a statement about God's favor being curried, who is "in" and who is "out." See especially the Social Science Commentary on the Synoptics by Malina and Rohrbaugh.

Imagine Palestine in the year 30 (thereabouts, dates are not precise). A Jesus of Nazareth is going around preaching a way that's different from the established Temple-based orthodoxy. Some listen to him and are persuaded by him, others aren't. Jesus followers can be found here and there, but by no means are the majority. The Jesus group is under constant threat from the religious/political/economic orthodoxy as well as the Romans. In this precarious situation, how should they protect themselves? Who can they call friends? I ask these questions because we have to understand the scenario that they're in. Doling out a systematic soteriology doesn't reflect Jesus' pastoral and practical concerns.

Being shown hospitality was one way Jesus' group could find friends. It wasn't necessarily that they would find other followers, but they could find people willing to protect guests, especially if they are unfriendly to the Romans. Jesus, broker and prophet of God, is able to extend God's blessings to those who grant his followers hospitality and (thus) protection.

In addition to Rohrbaugh and Malina, Jerome Neyrey, John Pilch, Mary Douglas and Zeba Crook have published on numerous relevant cultural aspects.