"Who is that 'He'...?" 

He is your own one God! 

"How He knows of my needs?" 

Because He is the Creator and also  looking after us! 

"How He knows even before I ask?" 

As He is looking after us, He knows! 

"If He knows what I need before I ask, 
- then why He has not fulfilled my needs?" 

He knows what we actually need  and 
when it has to be fulfilled! 

"Even if I ask Him, I have not received?" 

It depends on what we ask! 

"Will 'just knowing my needs', be sufficient,  solve, satisfy or fulfill my needs...?" 

It'll certainly be sufficient, solve,  satisfy or fulfill our needs, by 'just  knowing our actual needs! 

'As a man thinketh, so is he!' 

Our own inner-thoughts will be  our 
Actual needs. 

Let us be cautious in our  inner-thoughts! 

Let us be cautious in our needs! 

Let us be cautious in asking Him! 

Let us have faith that He knows! 

He will solve, satisfy and fulfill our  needs! 

He will lead us to live!