What in the Bible makes people think that time has a beginning?

What in the Bible makes people think that time has a beginning? I understand that Genesis says, "In the beginning....", but we use that expression for many things, such as "In the beginning, Mary thought that John was...." Gen.1:1 is not the beginning of everything. It is certainly not the beginning of God. It probably wasn't the beginning of Jesus. It probably wasn't the beginning of the angels (see Job 38:4-7 below that *seems* to imply that the morning stars and the sons of God pre-exist Gen 1:1). So why believe it was the beginning of time? Or why believe time has a beginning? Job 38:4-7 (KJV): >4 Where wast thou when I laid the foundations of the earth? declare, if thou hast understanding. > >5 Who hath laid the measures thereof, if thou knowest? or who hath stretched the line upon it? > >6 Whereupon are the foundations thereof fastened? or who laid the corner stone thereof; 7 **When the morning stars sang together, and all the sons of God** shouted for joy?