Death before sin?
This is one of the primary areas where many Christians (author included for years) have not thought this through to its logical, theological conclusions. And it has powerful consequences for how the kids we teach understand the God we so desperately want them to know.
Here’s the problem in a nutshell. No matter what idea a Christian may use to attempt to squeeze millions of years into the Bible— evolutionary creationism, gap theory, framework hypothesis, etc.—they all have the same problem of putting millions of years of death before Adam’s sin, which is a theological impossibility.
The Bible is explicitly clear, from cover to cover, that death came as a result of Adam’s sin (Genesis 2:17, Genesis 3, Romans 5:12, 1 Corinthians 15:21-22). Death is described as an enemy, the last enemy to be destroyed (1 Corinthians 15:26, Revelation 20:14). But if the idea millions of years were true, death existed long before man or his sin. That would make God the author of death who looked down on day 6, after millions of years of death, suffering, and diseases and called everything “very good” (Genesis 1:31).
This clearly impugns the character of God. And if death were indeed part of God’s original “very good” creation then why would He describe it as an enemy that would one day be destroyed? On top of this, the future hope of the Christian is that God will restore the world to it’s “pre-Fall” state. But if there were millions of years of death and suffering before man existed then what will God restore the world to? More death and suffering?
Most important of all, death is presented as the payment for sin (Hebrews 9:22, Leviticus 17:11, Romans 6:23, 1 Peter 2:24). But if there were millions of years and death before sin, then death is not the payment for sin. And if death is not the payment for sin, then Jesus’ death does not pay our sin debt and we are all still lost in our sins and bound for hell!
Thus the doctrines of atonement and salvation utterly collapse. That’s why the issue of the age of the earth is ultimately, a core, foundational issue and not a side issue. And that’s why we at AiG are so passionate about this topic! It robs the gospel of its soul-saving power! The gospel that’s based in the inerrancy and authority of the Bible!
 Even animal death has a relationship to human sin. The first recorded death of an animal in the Bible is in Genesis 3:21, which was a direct result of human sin. Animals were often sacrificed to cover man’s sin through out the Old Testament and were a shadow of the things to come in Christ (in other words, these animal sacrifices point to Christ’s [the Lamb of God’s] final and ultimate sacrifice).