Change time, times and half a time from 3.5 to 7.5 and divide 1260 by 7.5 = 1176 and then do a day for a year and you can get from 607 BCE to 570 AD - the birth of the Mohammed.
Replace Bible with a couple of magazines and don't let anyone keep back copies of the mags. In time replace mags with broadcast called Koran-t-truth. Don't let anyone watch old broadcasts.
Tell everyone God's a bit of a footballer - he has goals but no plans. Sometimes he has to change his entire strategy to accomodate unforesee emergencies.
Tell publishers they are all of the Aladdin Class - getting new light for old.
Job done.