Um, no, purpose isn't necessarily absent without God. Purpose is the intention that some being has in mind when they choose to do something. For instance, if there is a God, he had a reason, an intention, a purpose when he chose to create life.

People also have purpose when they chose to do things. When people lack goals, they fail to generate purposes for doing things, and thus they consider living, itself, to be pointless. When you say you are looking for purpose, you are just looking for something that can give meaning to your actions. God provides such a purpose... living up to the values and goals described by your religion.

However, this does not mean a God is the only source from which some can gain purpose. A person whose family was killed might live their lives for the sake of taking revenge on the killer. That is a purpose. A person who hates death might live their lives for the sake of conquering death. That is a purpose as well. God is only one solution to the search for purpose.