Demon days - D. L. Snell

While on vacation, journalist Sandy Travis and her fiance, Tom, are in a horrendous helicopter accident. Tom is seriously injured and has an N.D.E. (a Near Death Experience) where he sees a bright light and a figure who tells him that he must go back to the living because there's still more he must accomplish with his life. After Tom is revived, he tells Sandy that he believes he's spoken to God. As it turns out... Tom is wrong. Horribly wrong. The episode plunges Sandy into a dangerous race against malevolent forces who want to trigger Armageddon as foretold in the Bible. She must save her husband from the dark forces who suddenly control his life by following a bloody trail of coded secrets and targeted assassinations. Sandy's plight will pit her against an otherworldly cabal who use the process of N.D.E. as a way of orchestrating events that will usher in the Demon Days!