"I think it's Jerry's masterful fiction writing"

This quote by Tim LaHaye is referring to the fiction writing of Jerry Jenkins. LaHaye is revealing adoration for Jenkins' writing, suggesting that it is skillful. This implies that LaHaye thinks Jenkins' writing is of a high quality, which it is masterfully crafted. LaHaye likely appreciates the way Jenkins has the ability to create stories that are interesting and amusing. He might also value the method Jenkins has the ability to create believable characters and settings, and to craft a compelling narrative. LaHaye's adoration for Jenkins' writing is likely due to the fact that Jenkins is able to produce stories that are both satisfying and thought-provoking.