Let's talk a bit about the question "were you there?" It's common for Creationists to ask Evolutionists when they spit out their stories, but sometimes, Evolutionists to try to flip it back at Creationists. There are several problems with this.
First, this is called the Tu Quoque fallacy. The Tu Quoque fallacy is when a charge is turned back on the accuser rather than dealing with the charge itself. Even if you could show that Creationism has the identical problem to Evolution, that doesn't mean Evolution doesn't have that problem. It would just mean that all origins stories that do not come from witness testimony have the problem of non-observation.
Second, this is the straw man fallacy. The argument isn't "you weren't there, therefore it's impossible to know if Evolution is true". No Creationist would ever argue that personal observation is essential for knowledge. Not about science, not about history. No, the argument doesn't stop at "were you there?", but continues to "no one was there", and finishes with "except God".
See, the thing with history is that it's not generally visible to later generations. I didn't live through World War 2. I didn't sign the declaration of Independence, I never shook hands with Henry VIII, the Catholic Council of Toulouse never threatened to take my Bible, Julius Caesar's blood is not on my hands, you get the picture, I wasn't there. But someone was. I know that these things happened because people who were there told me so. Not directly, of course, but they left notes. But other questions were not recorded. Who was Jack the Ripper? We'll never know. That history was deliberately concealed by Jack himself/herself, possibly with help from accomplices.
But of course, Christians believe the Bible is the testimony of the Creator Himself. Not only that, but most of the Bible was written by direct witnesses and/or contemporaries. Even if we ignore divine inspiration, most of the historical events (particularly those in the New Testament) were observed either by the people that wrote about them, or by the people that the author interviewed. In fact, ironically, it was also primarily written to eyewitnesses and contemporaries. Which means we can be reasonably sure that yes, Jesus really did exist, He really did do His miracles, He really was crucified, and He really did rise again. And He really did affirm the authority of the Old Testament. Not just that, He explicitly quoted from Genesis as if it was positively asinine to ask Him about divorce when one could simply consult Genesis.
So, on the one hand, you have a bunch of made up stories about magical explosions, primeval soup producing single celled organisms, and all life on earth being ultimately descended from that cell. And I mean a bunch of made up stories. Seriously, as much as Evolutionists unite against Creationists, they divide against each other to the point where you can set them up debating each other. On the other hand, you have historical testimony not only from witnesses, but from God Himself. My friends, it makes no sense to ask a Creationist "were you there?" The answer is no, I wasn't, but Jesus was.
Jesus was also on the earth about 2,000 years ago. During that time, He verified His claims to be the Creator with various miracles, up to and including His death and resurrection. The latter two were specifically for you. See, the point of Christianity isn't the original creation, but the new one, and how we can receive our place in it. We sinned. We earned God's wrath. But on that cross, Jesus took it for us. But do you know what? He got up and walked out of His tomb. Darwin didn't. He's still lying in Westminster Abbey to this day, rotting like his ridiculous "theories". But Jesus, having been brutally beaten, hung on a cross and stabbed in the side, got up, walked around and wasn't shy about appearing to people to verify His resurrection. All you need to do to secure your place in the new creation is confess Him as Lord and believe God raised Him from the dead. Now, I don't know about you, but it makes a lot more sense to me to trust just one man who rose from the dead than a billion men who are heading to theirs.