Hello Jimbo,

No, you have things a bit mixed up.

Life emerged on Earth when there was essentially no oxygen in the atmosphere. Oxygen is actually HORRIBLE for the INITIAL emergence of life because oxygen is extremely damaging to various molecules. 

Oxygen was actually jettisoned as an unwanted waste product by the initial life forms. And as oxygen slowly built up, it became a toxic force that damaged the chance of any new life ever arising again from dispersed molecules.

What happened next was that, through mutations and selection, branches of offspring of the original life forms were selected for that could cope with the oxygen and even use the oxygen usefully.

We have our oxygen atmosphere because life arose, not the other way around.