Asking this question is akin of asking a school teacher if you can pass a class after failing an exam. Sure you might still pass the class (i.e. go to heaven) through very hard work afterwards (i.e. repentance), but your chances are very slim after failing an exam (i.e. committing a deadly sin like murder). Why wonder about it in the first place!?! Just do your best to avoid failing an exam (i.e. abide by the commandments that Jesus Christ affirms), and you will more than likely pass the class (i.e. go to heaven). May God bless you.