I guess you did not understand me , of course the sin is a sin (not tomato , just joking ) , the sin is not equal , as we agreed the sins are degrees (level) , (eg lie , not as killing , not as steal , ....) at the human being law and the God law .
don't tell that if you lie to some one it the same if you kill his whole family !!!
, but God as you said give his forgivenss...to each sin.
i will give you another good eg:
we have many kinds of cars : big car,small car , tall car ,short car,faster car,slow car, new car , old car , and the name of company and serie JMC, land rover ,honda ..etc, each one of them is a car , but they are different , its the same at the sin ....they are different