His testing room of suffering!
"I have tested you in the furnace of affliction!" Isaiah 48:10
I stood once in the test room of a great steel mill. All around me were little partitions and compartments. Steel had been tested to the limit, and marked with figures that showed its breaking point. Some pieces had been twisted until they broke, and the strength of torsion was marked on them. Some had been stretched to the breaking point, and their tensile strength indicated. Some had been compressed to the crushing point, and also marked. The master of the steel mill knew just what these pieces of steel would stand under strain. He knew just what they would bear if placed in a great ship, or building, or bridge. He knew this, because his testing room revealed it.
It is often so with God's children. God does not want us to be like fragile vases of glass or porcelain. He would have us like these toughened pieces of steel — able to bear twisting and stretching and crushing to the uttermost, without collapse.
He wants us to be, not hot-house plants — but storm-beaten oaks. He wants us to be, not sand dunes driven with every gust of wind — but granite rocks withstanding the fiercest storms! To make us such, He needs to bring us into His testing room of suffering.
Many of us need no other argument than our own experiences to prove that suffering is indeed God's testing room of faith. "Consider it pure joy, my brothers, whenever you face trials of many kinds — because you know that the testing of your faith develops perseverance." James 1:2-3
"When He has tested me — I will come forth as gold!" Job 23:10