Has your faith ever been tested? The obvious answer is, yes, a thousand times. Why is it important for our faith to be tested again and again?
Consider this metaphor? Why do car manufacturers take their cars to the test track and put them through all kinds of tests and driving conditions, pushing their cars to the limit? Because when their cars come off the assembly line, they want to be sure that their customers have a car that is roadworthy. They also want to maintain their reputation for manufacturing a reliable car.
God tests our faith because He wants us to possess faith that will endure no matter what trials we are going through. He wants to teach us that He will stand behind His work and His word, and that we can take God at his word and believe Him for the impossible. If our faith was never tested, it would grow flimsy and weak. But when we go through the fire of testing, our faith is strengthened for future trials.