I need to define what godless means first :
godless means to believe in nothing. To believe life is meaningless. That this life is just pleasure, instinct, and that the fittest shall prevail.
Many atheists believe in something, which can be wisdom, art, creativity, fairness, cooperation, knowledge, justice, peace.
They pursue these things, and their life is filled with meaning.
But godlessness is the rejection of all the positive values theists associate with deities. And trust me, there are theists who are godless, because they think religion is just a cultural figment.
So godless doesn't mean necessarily atheist.