And what does it mean exactly?

Existing in a more tangible sense, not existing as a concept.

Okay, and why exactly existing as a concept is less important for this argument?

Additional question — what religions do you know that explicitly state the existence of god in materialistic sense and not as a non tangible ideal (hence the word idea by the way)?

Please try to answer deeply and not just critisize me for hating atheists, I am not, I just point out very simple but overlooked details that are crucial for such discussions.