I've worked hard all day for my master. The least he could do is to thank me for working so hard. I deserve more than some of my fellowmen. They don't work as hard as I do. Because the Law of God convicted them of giving offense, of failing to call peoples' attention to their sins, of failing to forgive their sins when they confessed them.
Some people come to church loaded down with a guilty conscience.
Their sins make them weary. They simply need absolution, the forgiveness of sins. They need to be convicted. A mustard seed is very small but it is a genuine seed. Who takes away the sin of the world, to Christ who came not to be served but to serve, to give His life's ransom for many.