So, you have to make a sequel, but the original cast wants no part of it. Also, the plot of the first film makes a sequel logically impossible. Are you going to let that stop you? Of course not!
As the below movies prove, you're in good company! Well, you're definitely in company anyway.
Sequel To: Bruce Almighty
Evan Baxter, the anchor from the first movie. Oh, and God.
Congressman Evan Baxter is told to build an Ark, and he has to do it using ancient tools, because God is kind of a dick.
Why It Doesn't Work:
The first movie's premise was an interesting 'what-if' fantasy: "What if you had the powers of God?" Pondering this question while ignoring Jim Carrey as he twisted his stupid face around made Bruce Almighty almost tolerable. Evan Almighty takes this a step further and asks an even more thought-provoking question: "What if you had to build a boat? And also, you had a beard?"
For the sequel, news anchor Evan Baxter has become a congressman. How? Jim Carrey made him say a bunch of stupid crap on live television. You'd think saying "my tiny little nipples went to France" might make the campaign a bit challenging. Shouldn't God have mentioned this to Evan? "Hey, remember when you said a bunch of embarrassing stuff on live television, and how it's haunted you every day of your life, since it's totally unexplainable and frightening that someone else took control of your body? Yeah, that was my fault."
That's just the beginning of the dickishness from Evan Almighty's God, who presumably could have used His powers to prevent the flood, rather than have Evan build a stupid-ass boat. It's almost like they found it hard to write a family comedy based on the time God got mad and drowned the entire planet.