John 14:12, The Promises of Christ: the Greater Works

Jesus promised that His people would do works greater than His. It is nearly unimaginable what these greater works could possibly be. How could we ever outdo the Lord in terms of what He did during His ministry on earth? But the Lord gives this as the first of His three promises for the time of His physical absence from us. What are these greater works? And how should we respond if we are not seeing the greater works in and through our own lives?