This verse strikes home powerfully as it compares two extremes, lost in the translation into the English language. It has an enormous amount to say about discipleship in just a few words.
The Psalmist offers two states: being a doorkeeper at the temple or being a nomadic, wealthy, oligarch type of tent dweller (think mega 'glamping' not basic backpacking! Even more extravagant than a Dormobile!!!). The tent dwellers here are the wealthy, those that own enormous flocks of sheep, massive caravans of camels carry them and their wealth to the next pitching of the tent. Servants and slaves ensure that the camp is full of luxury and every whim is met.
The doorkeeper is... well, a doorkeeper. One who stands at the entrance of the temple or tabernacle and greets people as they arrive. There is some security duty but little glory, little engagement in the centre of worship, but there is clear, basic service to those who come to worship and especially to God. The doorkeeper is the first person who is met at the place of worship who points the way to go.
Our discipleship is about pointing people the right direction. Even in the most menial task. The washing up in the office kitchen needs doing even though it's not yours. You do it. That's doorkeeping. Someone needs to change the band chairs around to accommodate the parent and toddlers or lunch club. Even though you're not involved you do it. That's doorkeeping. The young people of the fellowship want a bouncy castle in the main worship hall for the community family day. Even though this is a special place personally, you help them put the inflatable up - and move the drum kit to accommodate it. That's doorkeeping.
Even the most trivial, humbling task in Christ's service teaches us more about learning from him than all the grandeur and glory we can imagine.
That's discipleship. That's mission.