So why don't you do something about this? Why are you silent now? This outrage! Evil men swallow up the righteous and you stand around and watch! Habakkuk 1:13b (MSG)
I learned as a father that, just because I choose to be silent does not mean I don't care. Sometimes I'm silent because there is a greater good that will be served by letting my child experience their current, momentary hardship. I can see the forest when my children can only see the giant tree in impeding their path. Sometimes I'm silent because maturity and wisdom come from having to struggle to work things out for yourself, and learn from the consequences of your mistakes and your successes.
And, sometimes I'm not silent, but my words have fallen of deaf ears.
When I experience God's silence, I try to remember what I've learned as a father.