The concept of God doing more than He explicitly revealed through the Bible ought not to be offensive. Scripture itself regularly gives only brief glimpses of people and communities which were part of God’s purpose.
Evolutionary Creationism is not unscriptural, it’s outside of scripture. There’s a major difference.
Scripture is our primary authority and subjects which sit outside of it are of less value and interest, certainly spiritually. However to say EC is unscriptural is misleading or just plain wrong. Yes, it is outside of Scripture, you can’t teach common descent or any other evolutionary science concept directly from Scripture. Is that the end of EC?
No. It is inconsistent of believers to declare a subject unscriptural (meaning against Scripture) just because it is outside of Scripture. There is an important difference between the terms. Gravity is not mentioned in Scripture but we have no issue with it. Ah but there are no doctrinal implications of gravity is the reply. Correct. So then to the question – what are the doctrinal implications of evolution and can they be disproved by a correct understanding of Bible? This blog contains exposition on relevant passages. If it was possible to prove definitively EC can’t fit doctrinaly using a consistent rational basis of exposition then the unscriptural tag would be correct – (note it would also create/maintain a host of problems reconciling God’s Word to His works which can lead to more risks to faith…)
My faith doesn’t hinge on God revealing the detail of how He did things. He created everything in a logical, ordered way for a purpose. I believe Genesis 1 fits into this type of revelation. The higher purpose of spiritual truth is unchallenged by a subject sitting outside of Scripture.