I don't think it is wrong to question the sovereignty of God. If you do, your faith in him will only grow. You will find out quickly that he everything the bible says he is. As for testing him, as in asking for a sign. What more of a sign do you need than the proficy fulfilled by Jesus Christ. You could spend the rest of your life studying the proficy fulfilled. As one example:
Ge 3:15 And I will put enmity between thee (satan) and the woman, and between thy seed and her seed; it shall bruise thy head, and thou shalt bruise his heel
How about Jesus on the cross being put into the ground on the hill called the place of a skull. His heal bruised the head when jesus saved us all.
Mark 15:22 And they bring him unto the place Golgotha, which is, being interpreted, The place of a skull.