Death, lurks everywhere

Life is there.

Death lurks everywhere as a silent assassin waiting on Satans mark.

Death hurdles at you, feasting upon you with content.

Once it's gone, all gone, you will soon be forgotten by friends, while Satan tortures family with memories.

You may deteriorate in the cauldron of fire and hell, or rise from the cauldron

as smoke into the Heaven above.

Death, lurks everywhere.

Well.. Since I can't be your friend while reviewing, I am going to be honest

Life is there.

Death lurks everywhere.

A silent assassin waiting on Satins mark.

First off I am guessing you meant to say Satan?
Also, the last line is awkward. You rhymed the first two lines, but then you threw a random line in there that doesn't.
You can still do a non rhyming poem, but then move that line so that the first two rhyme and the rest doesn't, but don't keep them in the same stanza

Death jumps at you with pain and grief.

Once it's gone, all gone.

You may be down below in the cauldron of evil, or rise from the cauldron

as smoke into the Heaven above.

Pretty good stanza, I like the cauldron reference.

Death, lurks everywhere.

Good, I like the repeat of the firstish (is that a word) line, helps make a theme.

Considering it's your first poem on YWS, it's pretty good.

78/100

You better not attack me at school tomorrow

Well since I don't know you at all...

First off. It was very short. It was a bit dull. You could have been a little more creative, seeing as you are talking about Death!

Life is there.

Death lurks everywhere.

A silent assassin waiting on Satins mark.

A bit dementing. The last line was weird. You have a strange way to tell us what death is like, but I'll go with the flow.(For now. Since you are new.)

Death jumps at you with pain and grief.

Okay first off. If you meant say that death is painful to the person it was inflicted on. How can death be painful if the person is already dead?
If you tried to symbolize that death is not just painful for the person, but also to the relatives, than it is okay. I'd try to clear that part up though. Try to make it more...clear.
Also, cant you find a better word than 'Jump' Seriously.

All in all: Nice idea. I just feel you can work on it more. Iyt is a bit sloppy for me.