"Scripture plainly teaches that salvation is conditioned upon faith in Christ, with no requirement for what one believes about the age of the earth or universe. ... people sometimes assume then that it does not matter what a Christian believes concerning the supposed millions-of-years age for the earth and universe." - Ken Ham
"In the several years since we initially received this question, young-earth creationists have produced many new materials....We have updated the answer with newer resources that will be of interest to those, like Tony, with questions about apologetics, intelligent design, and good resources to share with skeptics." - AiG
"Old Testament scholar and old-earth creationist C. John Collins argues that the lack of the refrain 'evening and morning' on the seventh day is a reason not to understand it as an ordinary day and therefore “makes us question whether the other days are supposed to be ordinary in their length.'" - AiG
"On June 5, 2018, a self-described Christian and professor of chemistry published a provocative blog post titled 'Talking Science as Christians.' The author, 'RJS,' under the guise of offering advice from a career in science, took young-earth creation (YEC) to task and sharply rebuked it." AiG
Having given reasons why young earth theology is essential to Christian doctrine as a whole, I now turn to a very popular argument that has been used against raising creationism to such a level. In 2004, Al Mohler wrote an influential article calling for theological triage.30 In that article, Mohler likens the sorting of doctrines according to priority with triage of variously ill patients in a medical emergency room. More serious injuries or illnesses are prioritized for faster response, whereas minor injuries are pushed toward the back of the line. Similarly, a doctrinal prioritization is visible in the historical development of doctrine in church history. Mohler calls for such sorting in today’s debates over doctrine and in the arrangement of churches and fellowships.
As a corrective to overreaction, Mohler wrote this in his article: