I was a stranger and you welcomed me...
Our world is a busy place. It teems with all sorts of activity; waves incessantly lapping on the shore, bugs crawling and flying; lions roaring, cars rolling, electrons connecting, viruses multiplying; angels hovering; demons manipulating.
Networks of human beings form a web that clothe the planet with children of God, and children of men.
To welcome a stranger is to link yourself to one of many possibilities. That stranger could become friend or foe. He could be an angel, or a demon in disguise.
Jesus says to start by assuming the stranger is He. One of the more curious Gospel passages took place after the Resurrection when Jesus appeared as a different looking person. His disciples recognized Him by Spirit, eventually.
Because of this trick, and because Jesus' ascension paved the way for the Holy Spirit to reside in humans, no one knows whether or not the stranger you welcome is a fractal of God.
Imagine the honor of hosting God. Imagine the awe. Imagine Jesus sleeping in your guest room. Imagine what you will serve Him for breakfast. Imagine having the opportunity to reciprocate for a fraction of what He has done for you.