An individual can be saved and love God and believe in an old universe and evolution. their growth and relationship with God does get stunted because they have to allegorize so many passages.
So you think Jesus was "stunting" our relationship with him when He spoke in parable and figurative stories? How do you think that happens?
On a larger level, when believers start revising scriptures that are allegorical, to make them literal history, then the world discounts the truth of the Word of God. St. Augustine warned us about such Christians, long before anyone knew about evolution:
Often, a non-Christian knows something about the earth, the heavens, and the other parts of the world, about the motions and orbits of the stars and even their sizes and distances, … and this knowledge he holds with certainty from reason and experience. It is thus offensive and disgraceful for an unbeliever to hear a Christian talk nonsense about such things, claiming that what he is saying is based in Scripture. We should do all we can to avoid such an embarrassing situation, which people see as ignorance in the Christian and laugh to scorn.
The shame is not so much that an ignorant person is laughed at, but rather that people outside the faith believe that we hold such opinions, and thus our teachings are rejected as ignorant and unlearned. If they find a Christian mistaken in a subject that they know well and hear him maintaining his foolish opinions as based on our teachings, how are they going to believe these teachings in matters concerning the resurrection of the dead, the hope of eternal life, and the kingdom of heaven, when they think these teachings are filled with fallacies about facts which they have learnt from experience and reason.
Reckless and presumptuous expounders of Scripture bring about much harm when they are caught in their mischievous false opinions by those not bound by our sacred texts. And even more so when they then try to defend their rash and obviously untrue statements by quoting a shower of words from Scripture and even recite from memory passages which they think will support their case ‘without understanding either what they are saying or what they assert with such assurance.’ (1 Timothy 1:7)
St. Augustine of Hippo,
De Genesi ad Litteram
YE turns many away from God, when they hear of YEC and assume that is what Christians believe. YE will have much to answer for at judgment.
Historically we had the greatest light ofScripture and now we are the most perverted nations on the land and will fall under harsher judgments.
I notice that prominent evangelicals are frequently much less Godly in their behavior than most Americans. Evangelicals have a higher rate of divorce, even greater than that of atheists. So it seems that you have it backwards.
And I notice that today, in a nation predominately Christian, our crime rates are dropping, sexual promiscuity is less common, and we are less likely to abuse people of other races and religions. So there's that, too.
One of the reasons is that believers listened to the devil when he repackaged the old lie to eve and said: "Does the Word of God reaaly say that,? Why can't it mean this???"
The devil told eve that she wouldn't die the day she ate from the tree, as God said she would. The devil turns out to be a Biblical literalist. She didn't physically die, but that's not what God meant. He was referring to a spiritual death.
And the devil told her that she would become like God, knowing good and evil, a fact which God later confirms to be true.
The devil is proficient at using the truth to mislead. And you should be acutely aware of that.