“every one of these commandments.” This translation of Deuteronomy 6:25—“every one of these commandments—tries to capture the fact that “commandments” is singular in the Hebrew text. A more literal translation of the Hebrew is “all this command,” but that phrase is not very clear in English, so the REV has “every one of these commandments.”
The point the Hebrew text is making is vital to grasp in order to understand how God considers His Word and His commands. God does not look at the Law as a bunch of commandments and if a person does most of them they are more righteous than if they do some of them. God looks at the whole law as a giant single command, and to fulfill the Law a person would have to do “all this command,” i.e., the whole Law without breaking a single commandment. Thus, Moses says that a person will be considered righteous in the eyes of God if they do “all this command,” but humans with sin nature cannot accomplish that, hence righteousness cannot come through the Law (Gal. 2:21; 3:21). In fact, we learn from Romans 4:3 and Galatians 3:6 that Abraham was righteous by trusting God before the Law, and David echoed the same thing under the Law (Rom. 4:6-8). It was by being humble and trusting God that people were declared righteous before God even under the Law (Ps. 51:16-17; Micah 6:8). Furthermore, there were signs all through the Law that being humble and trusting were what was important. For example, every sacrifice made was to contain salt, “the salt of the covenant” (see commentary on Lev. 2:13). The point of the salt was to reaffirm the covenant and one’s commitment to it, and to make it clear that no one could be righteous in God’s sight by just “going through the motions” of what God commanded in the Law.