Means: You think that there isn't any God, But as we all have needs, so.. what is your need ?
Im not sure of the assumption you are making there, though I suspect you might be projecting your own needs as a believer onto unbelievers. In my view there is a disposition or an emotional attachment that is apparent in some people, not necessarily a specific religious belief or an innate idea of God but possibly a genetic or inherited inclination that makes them suggestible to faith systems, which are reinforced by the family and or peer groups during the formative years.
The further view that there is a benevolent figure that will take care of us and has our best interests at heart is a very compelling notion. So in my view this disposition or inclination in some people makes them suggestible to the idea of a deity. The idea, often introduced at childhood, becomes ingrained and in adulthood the believer seeks to build a worldview around the idea, or a particular belief system may be adopted or adapted to fit with the conception.