Rejoice with those who rejoice; mourn with those who mourn.
Dietrich Bonhoeffer wrote that those who fail to listen to others fail also to listen to God. To help others, or receive help ourselves then, it would be the prerogative of the helper to listen well both to the one in pain and to God. Instead Bonhoeffer wrote that the cleric can go on and on in pious condescension with religious speak, having failed to hear anyone but themselves (my paraphrase).
When something good happens to someone which makes them happy, we should celebrate with them. That is especially true of those who belong to Christ and are thus in God’s family with us. When someone is mourning or in much pain, we need to listen well and make it evident that we empathize with them, even insofar as we can, sharing in their pain. As we hear not only their words, but also their heart, we can then be open to hear something of the heart and counsel of God for them, at least something of God’s heart, even if we don’t have much if any words to share.
If we do have some difficult words to share with them, they need to see that it comes from a loving, empathetic heart. God is not harsh, and if we’re going to speak for God, neither can we be either. It is all love, even if it is indeed hard words that must be spoken. Of course in all of this we need God’s wisdom. We may need to help them be ready to receive all that we would say. Or perhaps we need to test the waters by asking questions which can help draw out issues which need to be addressed. What we must avoid doing is simply writing off what they say as if it is nothing, while having our own ready answer. Our answer may (or may not) be spot on, but the one we are sharing it to may end up being repulsed so as not to receive it. God’s voice is different than that, and we need to reflect and speak from that insofar as we possibly can.