Let's say that one day, God comes down and says to you, "Look, I like you, so I'm going to give you a free pass to Heaven. You can do whatever you want, and you'll never be punished for it. Not in this life, not after you die. No matter what you do, you are guaranteed to get into Heaven." And he also proves to you beyond any doubt that he is God. So for the purposes of this thread, take it that it is actually God who is giving you this, not Satan in disguise or anything.
So, if you were given this assurance by God, would you go out and become a killer, thief, rapist, etc?
Are you asking if the end doesn't justify the means, whether the end will be appropriate?
I don't believe in Heaven or Hell, so I am trying to rephrase your question and your conundrum into a form my brain can relate to...
If Shiva gave me Darshan (holy appearance) and said to me 'you can have a boon, any boon you like' and I chose Moksha (enlightenment) would I go and kill people and do wrong things?
Well, if Shiva was to give me a boon and I wanted people dead, I wouldn't have asked for Moksha, but power, weapons, holy siddhis (mystic forces) and all that...actually, a lot of devotees who got boons from Shiva did just that...used them for personal greed and revenge...
So, after attaining Moksha or getting this 'pass to heaven'? would I think 'aha, I can do whatever I like now?'
Within limits...I mean, I am doing this already...I am still not the 'perfect human being', I still sin a
lot (drinking Irish Coffee while typing this), but I doubt I'd go and kill somebody, steal or do anything worse than what I am currently doing.
If it's not in my nature before the 'heaven pass', getting that free ticket, will not change who I am inside or what I do...so, nope...doesn't apply.