Compassion is about being open to helping the other and one way of doing that is by suffering with them and feeling their pain as much as you can. It involves walking with the other person.
Believers talk as if they think God suffers alongside them and is full of real compassion. Compassion is painful. Yet they say this is a metaphor. I don’t believe them. Even if they could not mean it literally, the fact is they are still trying their best to see God as truly compassionate. They are grasping at a vision – they are creating a painful tension. In principle they say if he can suffer for them he should and if he does not then that it a pity and a shame. To comfort yourself by God suffering or “suffering” with you is a form of selfish pride.