Honestly, but really really honestly and from a critical and questioning point of view to the christianity - some of those things (commandments, rules, guidelines) are very confusing. You cannot be saved merely by believing in Jesus, that is a fact. Human kind was saved by Jesus trough his sacrifise, but when you look at that from todays perspective... it didn´t last too long, didn´t it. World is a corrupted and evil place.
The one you try to explain there in your post, more looks like the doctrine of Islam 
, because logic says so if you believe in God and justice...
...