They exist now, yes. Purely chemical processes lead to the molecules that support life. They are self-assembling.
Then why doesn't life spout up all over the place?
Some plant, animal or person dies and there sits a whole pile of every possible molecule that could ever be wanted for a new life-form to spout into existence and yet nothing but death and decay happens. Even after weeks and months of decay, all the molecules that you say are needed for life to form spontaneously are still in huge abundance and yet, still, nothing happens. Even with the lion's share of the work done for it, life still can't seem to spout into existence even from recently living tissue!
And you know what? Nothing ever will happen either! No matter what you do, no matter how perfect you want to set up the lab conditions, no matter what other crap you add to the recipe or how much time you give it, all you will have at the end of your experiment is lifeless blob of goo.
Clete