The price that Jesus paid covers all sins, but if you do not repent, then He says that you will not attain salvation. That is one of the problems that Catholics have with most brands of the Protestants; we believe that you must repent of your sins - if there are sins that you do not know of, then a general repentence is called for. Nothing perfect will enter the Kingdom of Heaven; how will each person attain that perfection who is saved?
Still...this is leaving the door to hell open if one has not repented of thier sin and is struggling to overcome it.
Since alcohol has been mentioned lets say someone is struggling with that...we all know it’s a very real battle and hard to overcome. So let’s say they have started drinking again and for some reason die..car accident or just drink this time too much and keel over. No time to repent of this sin...so then because they fell once again and died then you are saying because they have not repented of this sin they are doomed for hell?