Does the Young Earth Creationist misuse of the scriptures and favoring their cherished traditions over the....?

Do Young Earth Creationist beliefs harm the credibility of the Gospel itself?

No. Unless you believe death happened before the Fall (when it clearly did not). Unless you believe certain literal stories in the Bible are metaphorical and not real life events (when many such events have been documented as being real). In fact, the belief in a Young Earth is what a normal person would have in a normal reading and study of the Scriptures. The only reason you would want to believe in an Old Earth is because of what secular science says and not what the Bible says.

Most Christians (such as myself) who stand behind the Global Flood, believe the Earth to be thousands of years in age and not millions of years old because they know the Bible and ancient civilizations to have been recorded as being only thousands of years in age.  Christians also know the Earth to be young because the tremendous amount of evidence that supports a world wide Global Flood, too.  In fact, this does not include the other different categories of evidences that back up the Scriptures, as well.  

Anyways, when secular scientists date fossils and rock layers, they don't factor in the Global Flood into their findings.  They make assumptions that the world is millions of years old and then date things accordingly. How do I know they make such wrong assumptions? Well, secular scientists had dated the findings of a recently erupted volcano to be a million years old. This means that they are biased towards dating things to be Old. Also, secular scientists claim that many rocks layers are millions of years in age, yet trees have been found growing thru out these rock layers, though.  Secular scientists also ignore the fact that sea shells on top of mountains would have not gotten blasted away by the elements if they were sitting up there for millions of years, too.  In fact, sea shells on top of mountains all over the world is one of the many incredible proofs that support a Global Flood and a Young Earth. Also, there are over 270 Flood Legends all over the world (With a good portion of them paralleling the various facts within Genesis). Fossil graveyards have been found buried all over the world. Trees have been fossilized standing up all over the world. Man's denial of a Global Flood (i.e. Secular Scientists and atheists) having fulfilled New Testament prophecy (2 Peter 2:3--6); And the list goes on and on.

However, what is the real problem with Old Earth Creatiionism?

Well, Old Earth Creationism not only does not line up with the scientific facts but it also sides itself with Secular Historical Science (of which cannot be proven because we do not have a time machine to actually show it's real age). However, thre real problem with Old Earth Creationism is that it is a model that came about from Evolution; And under the world view of Evolution you can technically do what is good and right in your own eyes. This is called "Moral Relativism" and it leads to chaos. In fact, under this World View: A person could say that when they murder someone, they are just one single celled organism eliminating another single celled organism by Natural Selection or survival. On the other hand, if a person were to believe in the Bible, they would be held accountable to a Creator God and a high moral code that tells them there is a right and a wrong.

In fact, the false "Theories" of Secular Science (Such as Darwinism, the Big Bang, and an Old Earth) runs contrary to God's Word. For they are faith based systems. Therefore if you take on such beliefs along with the Word of God you are trying to serve both God and this World. However, God's Word says....

"Ye adulterers and adulteresses, know ye not that the friendship of the world is enmity with God? whosoever therefore will be a friend of the world is the enemy of God."

In other words, you cannot serve two masters. You cannot side with the people of this World (who have their own faiths or theories) and also side with God in faith. God says that if you do, you will essentially make God the enemy. So tread carefully on which path you choose, my dear friend.

...

If you can't accept that the earth was formed in the 6 literal days of the Bible it all goes down hill from there. Think about it. If you can't take that seriously than how about Jesus ' s death? Did he really die on the cross as the Bible says? I'm not saying at all that you have to be a YEC to be saved or go to heaven but most non-believers want proof. If you take the creation story out of the Bible, they are more likely to wonder why they should believe the rest of it. I am not trying to offend anyone but God wrote the Bible and I sincerely believe we, as Christians should take it seriously! Hope this kinda helps or gives some insight.

It's tough to "kick against the pricks". Countering creation science has been going on for a long time, and it will go on for a long time. If creation science was pseudo-science there would be no need to "best counter". It may need fine tuning though.

Non-believers do not believe iin scripture. Thats why they are called non-believers. So no.

Col 2:8 Beware lest any man spoil you through philosophy and vain deceit, after the tradition of men, after the rudiments of the world, and not after Christ.

Please provide corroborated, credible, tangible evidence.

Thanks.