As we work our way through the second half of Matthew's gospel in today's readings, we find Jesus taking care of some of the "details" of the Kingdom he is establishing. He is reassuring the apostles that those who follow him, and suffer for it in this life, will find rest and peace in eternal life.
But before that we have the recurring lesson that I can't reach heaven by my own efforts. In the discussion about camels pass through needles easier than the rich enter heaven, The disciples say: “Who then can be saved?” Jesus responds, “For men this is impossible, but for God all things are possible.” Self-reliance, a virtue Americans in particular love ( "pull yourself up by your bootstraps" sort of mentality), fails us when it comes to getting to heaven. Jesus knows that we want to be self reliant, and so he continues to repeat this lesson that this doesn't work. You can't earn heaven. You can't work for heaven. You can only accept heaven as a gift from the God who loves you more than you deserve.
But nonetheless, work and do good. Do good for God by doing good for others. This is the proper response to God's love for you.