The Protestant view of justification largely hinges on their definition of "righteousness." In the Protestant view, to be justified one must be righteous, and to be righteous one must have kept all of God's commandments perfectly. It's akin to needing to score a 100% on the SAT, with anything less than 100% being a complete fail in God's sight. In this post I will go through the Bible and show why the term "righteousness" does not mean "perfect law keeper" or anything similar, which in turn will totally undermine the Protestant understanding of salvation and the Gospel.
The Greek words for "righteous" ("just") and "righteousness" are used a few hundred times in the Bible, so if the Protestant thesis is true, there should be some clear evidence for it. Most of the occurrences uses the terms "righteous" and "righteousness" in passing, so not much can be gleaned from the bulk of the texts. That said, I did not find a single instance where "righteous" or "righteousness" was tied to perfectly keeping the law or commandments. This means that the Protestant definition does not come from the Bible, and rather from traditions of men. Instead, the notion of being righteous, according to Scripture, simply refers to doing good actions (e.g. Mt 6:1; Acts 10:35; Eph 6:1; 1 Th 2:10; 1 Jn 3:7,12) or having an upright quality about your character (e.g. Mt 1:19; Lk 1:6; 1 Tim 1:9; 1 Pt 3:14). Nothing is ever implied about perfect or flawless obedience.