"seventh grade" is a narrative. how is this form of writing different from a persuasive text?

in my opinion, anyone should be allowed to marry as long as it's not going against any laws. though i kind of contradict myself because i know that in some states and countries, gay marriage isn't legal yet- hopefully you get my point.

the development of trade during the middle age increased to the change given in the agriculture, which gave money, industry and markets a bigger importance in economy. the agriculture production was more than the consumption, which meant the creation of wider markets out of the areas. besides, with the end of multiple wars, the population increased and new trade routes were created.