That's hard to answer I think but I think the reason God's infinite is cause of the faith that is put into him. When the faith stops then so does he. It's like we won't even matter here on earth after a few generations. Only my family and immediate family and kids and grandkids and maybe great grandkids would know I even existed and was alive, so after they die, so will the knowledge of me. So I suppose it's the same for faith, until the last person of faith draws their last breath God will be infinite. If that makes sense. It sounded better in my head. Delete if this is not what you even ment. Im sorry.