Saguna (Idol) Worship has got this capacity to give peace of mind because there is chaitanya in the idol installed in the temple and after pouring out our suffering before God in the temple, we get some peace of mind.
That is why we have the habit of going to the temples.
Of course, some people do not go to a temple at all, but they go to a river or a lonely place and weep there for some time and they then come back with peace of mind.
People get peace of mind wherever there is no reaction to what they say. So, a suffering man goes only to those places where there is no reaction to what he says.
When one prays to Ishwara, one gets mental peace, because Ishwara does not talk at all. If Ishwara starts replying, then we shall start talking something more.
After all, Ishwara knows everything and He will give us whatever we want. Of course, this does not mean that God will give us exactly what we ask for.
He will give us only that much which will give us peace of mind, though He has the capacity to give everything that we want.