One little word in Greek (and, then, a few words in English—depending on the translation) makes all the difference for how we understand a believer’s relationship to sin.
When the New Testament writers quoted the Old Testament, their quotations didn’t always come from the original Hebrew/Aramaic. In fact, somewhere between 90-95% of the time, their quotations came from one of the Greek translations of the Hebrew/Aramaic Old Testament.
One of the great things about giving your time to biblical studies and regular bible reading is—like with most things—you start to see things you never saw before.