To get mathematics in line with the precepts of fundamentalist Christianity, the authors have tried to fuse mathematics with fundamentalist theology -- and have succeeded in straining their credibility to the breaking point.
"A line can be described either by its slope (a ratio) or by its inclination (an angle). These terms describe the deviation from the horizontal, but the word inclination also has a non-mathematical meaning. Without Christ, man is inclined to sin. The Word of God should shape our attitudes (inclinations)." Huh?