There are many different teachings here in Matthew 19 which can be highlighted. Jesus does his second teaching about divorce in Matthew, then moves to working with children. After that, one of my favorite discourses in all of scripture, the Right Young Man. At the end of all these teachings the disciples, who have heard all this, wonder what will happen to them. The difficult teach from Jesus regarding the challenge of the rich entering the kingdom, has them a little unsettled.
The disciples have given up everything to follow Jesus. They are rarely perfect in their following, yet they have staked their lives to the work, mission and ministry of Jesus. The fishing business that once fed their family was walked away from. The family support they enjoyed was undoubtedly compromised. Now they want to know what was in it for them since they have in fact given up everything.
We modern day followers of Jesus wonder the same question, but I am not sure our question has the same leverage. Many have given up much, but in the Western world we have rarely given up everything. Still the question lingers, what is in it for me? What will the reward be for my sacrifice? When you write the question it feels more foolish than it sounds.
Jesus response then and now is intriguing. He says all these things will be given back to, only multiplied. Then he tags it with a common saying. The first shall be last and the last shall be first. Letting the disciples know it is not about the stuff, it is about connection with God through him. Saying more about me perhaps than anything else, I read this with a sense of sarcasm. Jesus is saying if those things mattered the kingdom would offer the best and more than can be imagined, but those things do not matter.
The reward for following? Doing what we are designed and created to do.