What you made mention of is the same as saying, "I'm sorry for beating my wife, and I repent and trust you Christ" and then going home and beating your wife again until she is dead, and then praying to Christ for salvation saying, I'm sorry for killing my wife Lord and I repent of my sin, and trust in Christ."--in order to be saved and go to heaven after death. i.e., Christians are being rewarded for bad behaviour with this philosophy. No consequences for the believer unless of course the secular courts have anything to say about it.
In reality according to your Bible, you MUST repent of ALL sin and trust in Christ for salvation, and if you WILFULLY sin again after being saved, you go to hell--as the Bible tells us.
Let me interpret the gobblydygook you say is an accurate representation of Christianity. That is:
"In the Christian belief, a person counted righteous by God when God counts the righteousness earned by Christ's obedient life to that person, by God's free grace. "
What this really means is that you have no say in your 'righteousness'--that's all on your Christ. i.e.--you don't have to take responsibility for your own behaviour. It's 'earned' by Christ, not you--as you made mention. Furthermore, by God's grace. i.e.--you don't even get to choose. No free will to choose to believe as it is by 'God's grace." Not you. Nothing is on you. You have free reign to do whatever you want including murder, theft, etc,. as long as you repent afterwards and of course 'believe.' Again let me reiterate just how abominable this philosophy is.