A Writer's Ramble:

Writing is Visual

Writers need to know how to write. They need to know basic grammar, sentence structure, spelling (or have a good dictionary/spell-check) and how to lay out dialogue. Now, I don't pretend to be an expert in grammar; I make plenty of mistakes and typos in my work. However, I do have a basic understanding of grammar and spelling. Moreover, I've learned how to use those skills to write a story.
Therefore, I'm giving aspiring writers this piece of advice:

Writing is a visual medium.
When someone reads your work, they see it. If they see a sloppy, loosely edited, badly composed story, it will relay a message: This person does not know how to write. It won't matter if your story has fascinating characters or a stunning plotline if someone quits reading after the second paragraph; poor grammar and sentence structure can make a reader feel it's not worth the effort.

Here's an example of bad grammar and spelling:
It was night and I was standing in the rain the cold wet seeping into my skin and hair. I had closed my eyes and I could hear the thruming of the raindrops as they hit the ground but it was a heartbeat I was trying to hear. Ah there it was the faint thumping sound and I licked my lips. I had found my quarry and she had already been pursued for three city blocks but now the search was nearing an end. "She is close." I let the words carry over my sholder to the rest of my team and I signaled and we moved left and down the dark street. I had brought my five best men all well trained and with practiced ease we assembled formation and advanced on the hunted and I was on point tracking all my senses open.

A better version:

It was night and I was standing in the rain, the cold wet seeping into my skin and hair. I had closed my eyes, and I could hear the thrumming of the raindrops as they hit the ground. But it was a heartbeat I was trying to hear.
Ah, there it was, the faint thumping sound.
I licked my lips; I had found my quarry. She had already been pursued for three city blocks, but now the search was nearing an end.
"She is close."
I let the words carry over my shoulder to the rest of my team.
I signaled, and we moved left and down the dark street. I had brought my five best men, all well trained. With practiced ease, we assembled formation, and advanced on the hunted. I was on point, tracking, all my senses open.

There are spelling errors in the first version, no paragraph separation and not enough punctuation. In addition, the dialogue is not handled correctly in the first narrative. Which version would you want to read?

An example of badly displayed dialogue:
"Ah, a convert of Jacob." Lorenzo's voice sounded forlorn. "I am proud to belong to Jacob." Cecily's reply held a note of jubilation, but it brought only anxious murmurs from the Council; I could smell their fear. Lorenzo continued. "You know there is a standing edict regarding all followers of Jacob? You are aware of it?" Cecily nodded. "Then there is no need for this trial. This Council will never support the ravings of that power mad fool." "He is no fool! He is right! We must fight! We must be the dominant species!" "Silence!" Lorenzo's voice shook the walls.

A better version:

"Ah, a convert of Jacob." Lorenzo's voice sounded forlorn.
"I am proud to belong to Jacob."
Cecily's reply held a note of jubilation, but it brought only anxious murmurs from the Council; I could smell their fear.
Lorenzo continued. "You know there is a standing edict regarding all followers of Jacob? You are aware of it?"
Cecily nodded.
"Then there is no need for this trial. This Council will never support the ravings of that power mad fool."
"He is no fool! He is right! We must fight! We must be the dominant species!"
"Silence!" Lorenzo's voice shook the walls.

In the first paragraph, none of the dialogue is separated and it is difficult to distinguish the speakers. In the second version, you can see the flow of the dialogue.

An example of a run-on sentence:

I am of the Elite and serve the Vampire Order, we have been the guardians over vampire kind for nearly two centuries and the Elite keep the secrets, implement the edicts and we protect our kind, punish wayward individuals, enforce our law and that law is simple, you hunt the invisible, the homeless, the drug addicts, or you disguise the kill as a mugging gone wrong, a serial killer never caught.
A better version:

I am of the Elite, and serve the Vampire Order. We have been the guardians over vampire kind for nearly two centuries. The Elite keep the secrets and implement the edicts. We protect our kind, punish wayward individuals, and enforce our law. That law is simple; you hunt the invisible, the homeless and the drug addicts. You disguise the kill; a mugging gone wrong, a serial killer never caught.

A reader needs to pause, to feel the rhythm in a sentence. If the entire paragraph is one sentence, there is no break, no flow.

You can rift and free write or jumble down your thoughts to your heart's content if you are the only one who is going to read it. The minute you decide to share your work, a thought to presentation must be given. Your writing is a gift to your readers, don't wrap it in wrinkled and soiled paper.