How can I am (God) so merciful can punish you ?

I cannot punish or reward you based on your evil and good actions 

it is you who punish yourself through evil actions or free yourself from through right actions 

Actions attained to the WILL of the spirit 

Man form his future by his actions 

A good or bad action spreads its vibrations and become known throughout the universe 

The more spiritual you are 
The stronger and clearer the vibrations of your actions which spread over the world and weave your future 

The universe is like a dome 
it vibrated to that which you say and echoes the same back to you 

So also the Law of Action 
I reap what I sow