When a church is falling and loses its desire for good, those within it who desire what is good will grieve. That's the state represented by "mourning" in the Bible. On a personal scale this also happens inside us as we move from lower spiritual states to higher ones. To be "comforted" represents an influx of new ideas which can help us move on to a new spiritual state or – on the wider scale – can help rejuvenate or even replace the church.

Here, then, we see the Lord promising the good people of the Jewish church - the ones grieving over its fallen state and the self-serving ways of its leaders – that they would receive ideas that would let them move on to the new church he was establishing in the world.

The word "righteous" has taken on a bit of negative shading in modern language. That may be because we hear it most often as part of the word "self-righteous," a rather scathing term for someone who thinks he is quite a good person -- almost certainly better than anyone around him -- and is in a position to judge others without being judged himself. The original word, however, is not negative at all: A righteous person is simply someone who does what is right. The spiritual meaning of "righteous" reflects that: people described as "righteous" act from a love of serving others, and that love is "righteousness." This is commonly described as "the good of charity," "charity" meaning a state of caring for others.