Luke 21

v1-4: Jesus Christ sees what we give to the work of the gospel and the relief of the poor.  "He notices whether we give much and generously, in proportion to what we have, or whether we are mean and give as little as possible. In fact, he looks even further: he watches to see whether we give charitably and with a willing mind, or grudgingly and with reluctance."

v5-19: The disciples ask, 'When?' and Christ's response is, 'Watch out that you are not deceived.'  This reminds us that "those who are most inquisitive about the things of God—though it is very good to be so—are in most danger of being deceived and need most to stand on their guard."  When we are convinced that Jesus is the Christ and that the gospel saves, "we must be deaf to all suggestions of another Christ and another gospel."

v20-28: The destruction of Jerusalem was a kind of appearing of Christ and an act of His judgment.  It previews the terror and destruction that is coming to all unbelievers when Jesus returns.  On that day, those who refused in this life to see that He came first to save them, will be made to see Him coming to destroy them, as the unfaithful Jews did.

v29-38: We must watch and pray always.  Both to keep guard on ourselves and to maintain fellowship with God.  Knowing that the Lord is coming again, we need to "watch against sin, and watch [ourselves] to make sure you do every duty and make the most of every opportunity to do good" so that we will be counted worthy "to lead a life of praise in the next world."