A God who makes mountains tremble is a problem for frail, sinful people.
Such holiness and majesty that makes mountains quake is hostile to our lack of holiness.
The language of the Bible on this matter, so we are told, is dated and outmoded.
But we know our moral brokenness, our sin, is not removed by it being unpopular or inconvenient.
The gospel of Good News only makes sense when we understand the bad news of our brokenness.
Of course God did not make us broken—humanity chose that path.