It will be therefore to our merit before YHWH Eloheinu to observe faithfully this whole instruction, as He has commanded us. Deuteronomy 6:24 (JPS translation with name corrections)
Merit – After the Reformation, verses like this one are difficult to integrate. Perhaps that’s one of the reasons that Christianity created the chasm between the “old” Israel and the “new” Israel. It was so much easier to simply say that the idea of meritorious behavior belonged to the old covenant of Jewish “works” while the new (and improved) theology of Christianity rested securely on grace alone. As we recover the Hebraic foundation of our faith in YHWH Eloheinu (YHWH our God), we sometimes feel quite uncomfortable with the sola gratia emphasis of orthodox Protestant Christianity. All of this results from a basic misunderstanding of the Hebrew idea of righteousness (tsedaqah).
The paradigm verse of Jewish Hebraic tsedaqah is Genesis 15:6 (cited by Paul in Romans 4). Abraham believed in YHWH and it was credited to him as tsedaqah. In addition to “righteousness – merit” (tsedaqah), this verse has two critical verbs. The first is “believed” (he-emin). The verbal root is ‘aman. Often translated “trust” or “believe,” the primary meaning is to be reliable, firm, established. In other words, Abraham took God’s words as completely reliable. He build his actions on them. He established them as the bedrock of his life. For this reason, tsedaqah was “credited” or “reckoned” to him. This second verbal root is hashav. It has a wide umbrella (to think, to devise, to invent, to consider, to regard, to be accounted, to reckon oneself). Some of these meanings are limited when God is the subject. That is the case here. So, we normally translate this verb as “reckoned” or “accounted.”
Put aside any pre-commitments to Reformation interpretation and ask yourself, “What is the face-value meaning of this verse?” Isn’t it obvious? Abraham trusts what God says and God counts that trust as tsedaqah, as if Abraham had earned merit before God. Of course, in one sense Abraham didn’t earn anything. He didn’t earn “saving faith” because God granted it to him. Righteousness was credited to Abraham. It was a gift. Abraham could never have demanded it for it was not his to earn. God has to count this act of faith as if it were tsedaqah.
On the other hand, Abraham did do something, didn’t he? He chose to believe! He decided to accept what God said as the reliable foundation for his actions. This wasn’t cognitive assent. This was the basis for Abraham’s life. He staked everything on God’s promise, so it isn’t as if Abraham is completely passive here. Unless he makes this choice, there is nothing that can be counted as righteousness. Abraham decides to count on God. God decides to accept Abraham’s choice as if it is tsedaqah. From the Hebrew perspective, both are needed. No human action is completely righteous by itself, but human actions that express faithful reliance on God’s word can become righteousness because God will count them as such.
Now we can understand why Jewish interpreters of this verse in Deuteronomy say “one accumulates credit for meritorious deeds.” “The concept is like that of acquiring ‘principal’ in the Talmudic idea that ‘a good deed yields a principal and bears interest,’ as in the list of ‘deeds whose interest one uses in this world while the principal remains for the hereafter.’”
Is it possible to do good deeds that God counts as tsedaqah? Of course it is. Does this mean that we can earn our way into His presence. Fortunately, no. This is fortunate because no one is able to do all that is necessary to be completely righteous, so we must all depend on God’s compassionate grace to extend righteousness to us – and quite fortunately, He is willing to do that. But His grace does not remove the possibility that our faithful obedience doesn’t count at all. It does. Every act of obedience redeems the earth and glorifies Him. It matters. Oh, yes it does!
Topical Index: Genesis 15:6, Deuteronomy 6:24, Psalm 106:31, tsedaqah, righteousness, ‘aman, hashav, merit
 Jeffrey Tigay, The JPS Torah Commentary: Deuteronomy, p. 83.