Many useful comments here, in spite of the favorable mention of Roman Catholic holy-days (Easter and Christmas) and some seeming confusion between the ideas of free will, free agency and (what the theologians call) "the power of contrary choice."
Dr. A.E. Wilder-Smith was one of few scientists in the world to have three earned doctorates.
A devout born-again Christian, a devoted husband and father of 5 children, a young-earth creationist, and a highly qualified organic chemist, he authored over 70 scientific publications and more than 30 books, some published in 17 languages.
Many of today's leading creationists consider him a major influence in their own intellectual development, and call him a pioneer in anti-evolution arguments. See http://wildersmith.org/testimonials.htm for testimonies about Wilder-Smith by Duane Gish and other scientists and intellectuals.
He was not only an expert on chemotherapy, pharmacology, organic chemistry, and biochemistry, but a gifted teacher and popular public speaker. He appeared prominently in an award-winning creation film series called 'Origins: How the World Came to Be' (at http://christiananswers.net/catalog/or-vs.html).
Wilder-Smith debated Richard Dawkins. This debate is on CD at http://www.sermonaudio.com/source_prodinfo.asp?PID=ad81206173621).
More at http://www.creationsafaris.com/wgcs_5.htm
Free Puritan books and MP3s on-line at the 'Outside Web Link' below.