Here's a scripture I just came across while reading 1 John this morning, where you can see, from the context, that John is using the word righteousness with the Jewish sense of tzedakah, meaning helping the poor.
“10 In this the children of God are manifest, and the children of the devil: whosoever doeth not righteousness is not of God, neither he that loveth not his brother.” (1 John 3:10, KJV)
The 'doing not righteousness' and 'loving not your brother' always read a little odd to me. They seemed to be parallels, referring to the same thing, but in English the parallel didn't make much sense.
Now lets try it substituting tzedakah*, for righteousness.
“10 In this the children of God are manifest, and the children of the devil: whosoever doeth not righteousness (tzedakah) is not of God, neither he that loveth not his brother.” (1 John 3:10, KJV)
Well… 'doing not tzedakah' sounds exactly like something a jew, like the Apostle John, might say, but can it possibly be what he is saying? Is he making a parallel between not helping the poor, and not loving your brother?
Read on to verses 16 and 17:
“16 Hereby perceive we the love of God, because he laid down his life for us: and we ought to lay down our lives for the brethren.
17 But whoso hath this world’s good, and seeth his brother have need, and shutteth up his bowels of compassion from him, how dwelleth the love of God in him?” 1 John 3:16, 17, KJV.
Wow! That appears to be exactly what John is saying, because here, 7 verses later, John clearly parallels loving your brother with helping those who are in need. Seeing your brother have need and shutting up your bowels of compassion toward him is what 'doeth not tzedekah' would mean to a jew.
* The word translated righteousness in this passage is the Greek word dikaiosune, almost always translated into English as righteousness. The Hebrew word usually translated into English as righteousness is tzedakah, but, as a quick google search will reveal, tzedakah has an idomatic meaning, helping the poor. The Gospel of Matthew 6:1, Paul in 1 Corinthians 9, and Luke in Acts 10:35, and now 1 John all use the Greek word dikaiosune with this Hebrew idiomatic meaning.