Okay, here's the deal. You have to write your own gospel account.
Should I say that it has to be for the church you're a part of? That would make it more interesting.
Should I also say that none of your readers will have access to any of the four gospels you know so well? The plot thickens.
Even better, what if you know that your account will have to compete with the others that are available? By the way, is this the author's assumption in Luke 1:1-4? And is this why John is so different? Were Matthew and Luke and John all thinking, "There's a better way to do this"?
For what it's worth, I use the names of the four evangelists for the sake of convenience. I don't assume I know who wrote any of the gospels, although I like the traditions and have no reason to reject them. And that raises another interesting question, How would it impact what you wrote if your gospel was anonymous? Or if your identity might be suspected, hinted at, but heavily veiled?
Anyway, in writing your gospel, you can use only what's in Matthew, Mark, Luke and John. No new material (like you have any). Nothing from the apocryphal gospels (would you really want to?). Yours will be a sort of new creation using what's already there.
Also, you can't do a harmony of the gospels, where people include all the material from all four. In fact, like the four accounts we have, you will have to leave out a lot that's found in one or more of the other three. For example, you can have one birth story (Matthew's with the magi) or you can have the other (Luke's with the shepherds). But you can't have both. Or, like Mark and John, you can have neither. Etc.
Ready? Now for a few questions:
1. What major segment (miracle story, parable or sermon of Jesus, etc.) are you sure to include? Why?
2. What major segment are you sure to leave out? Why? Oh, and in response to this one, you don't get to say, "I'd leave out John 7:53-8:11 or Mark 16:9-20 because I don't think they're authentic anyway."
Bonus: How much difference does it make in your choices if this gospel of yours has a specific destination? For example, what if your gospel will be the account used in a suburban church in the U.S.? Or in a church in a small village in India that's dominated by Hinduism? That is to say, What happens to your choices when they're guided not by your personal preferences, but by what you perceive to be a certain groups' needs? And would a person ever write a gospel without having a particular ideal audience in mind in the first place?