I think it must be really comforting for many a former Nazi family member to know that, no matter what they did during WWII, their loved ones are in heaven.
You have to understand that Reformed theology is a legal creation. It is based on rationalizations if not on naked rationalism, and not on love. In their mind, no matter how bad their client might be, they can always get him off the hook.
They take Matthew (12:37) as gospel
So, no matter what you do, you can be saved if you say the magic formula.
And here I thought they believed one is justifed by faith alone.
Astounding. The fact you dismiss this core belief of Christianity positions yourself outside the church of God and contrary to God's word...again.
"For ye are bought with a price: therefore glorify God in your body, and in your spirit, which are God's." -- 1 Corinthians 6:20
If you think that you can pay God for any sin you commit you are in state of strong self-delusion.
Try reading 1Jn.1:9.
I know the concept of grace offends you, but it was God's choice to send His Son to die for the sins of the world (1Jn.2:2), and make the only requirement for salvation accepting the free gift of salvation (Eph.2:8-9).
Now, when you and the rest of you
religious types who reject Grace get to the Great White Throne Judgement, you will be judged for your works not your sins and you will see that will only get you sent to the Lake of Fire, no different than any other type of sinner.