The centurion who speared Christ also guarded the tomb. When the body is missing, Pilate orders his arrest. He flees. The spear has special powers. An angel orders him to write a manuscript and hide it. He writes a second manuscript and hides it, before being captured by the Romans in Ephesus. He writes his final testimonial, then hides it along with the spear.
After an earthquake in 2030, one of the manuscripts is found by two American archeologists. A hunt for the other manuscripts and the spear follows that takes them to Jordan, Israel, back to Turkey and finally America.
America has become very secular, and there is legislation proposed to limit Christianity in America. It will be voted upon on Good Friday. When word gets out of the found manuscripts a chase follows. The Christians want to publish it, and the atheists and Muslims want to destroy it.