My sister lost her husband and she is furious at God. I do not know what to say and I am frightened of saying the wrong thing.

“So they sat down with him upon the ground seven days and seven nights, and none spake a word unto him: for they saw that his grief was very great.”

Job's three friends do exactly one thing right in the whole book. They come, they see him from a distance, and they sit down on the ground with him for seven days and seven nights without speaking, because they could see how great his grief was. Everything goes wrong the moment they open their mouths and begin explaining. The silence was the ministry.

“Rejoice with them that do rejoice, and weep with them that weep.”

Paul's instruction to the Roman church is only a few words long and asks them to match the sorrow standing in front of them. It sits in a list of ordinary church practices, right beside hospitality and sharing money. He adds no clause about correcting the weeper's theology first. In Paul's churches this was normal Christian behavior rather than an advanced skill.