Are the tests such as divination before Guanyin spirit credible?

Not credible. If you are in trouble, you can recite Buddha, set free, recite scriptures, ask bodhisattva for help, be responsive and sincere. You will be full of hope. You can read more employment stories to increase your confidence. As for fortune telling, can it be changed? Bad luck means bad luck, and no matter how you hide, it won't change. If you practice Buddhism, you can change your destiny and avoid bad luck. Specifically, you can see Fan's under the temptation, as well as Guanyin Lingqian. The most important thing for people is to change their lives, not to tell fortune. Amitabha.