The נהנה's final speech

The נהנה seems to have a drastic change in philosophy in his final speech in Kohelet. Previously he believed that the reason הכל הבל was because G0d controlled everything, so what was the point of doing anything if G0d is going to give you what you need. You might as well eat, drink, and be merry. But now he is claiming that there is no G0d at all and that nothing matters in world because there is no after world, so there is nothing to accomplish. Do whatever you want because there is no משפט after death. 

He also mentions something that I do not agree with. He says that everything is הבל because good things happen to the wicked and bad things happen to the righteous and this is why the world is הבל. This implies that he does not believe that there is a G0d to regulate and control the world. 

I understand his reasoning why he thinks there is no G0d, but it could also be interpreted as there being no משפט in this world. According to the statement above about unfair treatment, it doesn't eliminate the possibility of having משפט in the next world. Why does the נהנה go straight to the conclusion that there just isn't any G0d at all? 

The נהנה seems like a pretty lazy character. He doesn't seem like he wants to put much effort into anything. I think he went straight to this conclusion because he didn't feel like having to work towards anything or to exert anything he doesn't think is worth it. If he believed there was a reason to be good he probably still wouldn't, and he would be given a bigger sin for knowing he needed to be good but ignored that. 

SORRY IF THAT LAST PARAGRAPH IS CONFUSING....