How did christianity change in the first 500 years since its emergence?

As a fellow catholic, christian I can say a lot has changed in the first 500 years.

-There is less killing people for it, but there are still victims in this world.

-People can either be serious or not serious about the religion

-The Pope's have gotten better over these centuries and are more serious.

-There are many religions based off of this one actual religion.

-People have been persecuted for their faith, but in a less murderous way.

-We have the ability to start fighting for what we believe in (as in our faith).