Phinehas justified by works??? Psalm 106:30-31

Yes it is talking about the set-up prior to calvary. This set-up will be re-instated after the rapture also.James is written to the twelve tribes. vs.1
Col. 2:13 And you, being dead in your sins and the uncircumcision of your flesh, hath he quickened together with him, having forgiven you all trespasses;
14 Blotting out the handwriting of ordinances that was against us, which was contrary to us, and took it out of the way, nailing it to his cross;
15 And having spoiled principalities and powers, he made a show of them openly, triumphing over them in it.
16 Let no man therefore judge you in meat, or in drink, or in respect of an holyday, or of the new moon, or of the sabbath days:
17 Which are a shadow of things to come; but the body is of Christ.

"shadow of things to come" The Old Test. set-up is going to be re-instated.

Here is Abrahams righteousness;
James 2:23 And the scripture was fulfilled which saith, Abraham believed God, and it was imputed unto him for righteousness: and he was called the Friend of God.

That reference is in Gen. where Abraham believed God's promise about his seed.

Gen. 153 And Abram said, Behold, to me thou hast given no seed: and, lo, one born in my house is mine heir.
4 And, behold, the word of the LORD came unto him, saying, This shall not be thine heir; but he that shall come forth out of thine own bowels shall be thine heir.
5 And he brought him forth abroad, and said, Look now toward heaven, and tell the stars, if thou be able to number them: and he said unto him, So shall thy seed be.
6 And he believed in the LORD; and he counted it to him for righteousness.

Do a word study on righteousness and see what God says about it.

 

Reading the account in Num 25 shows that Phinehas had God's jealousy against other gods. This evidently came from faith in the true God, giving him the zeal for God that caused him to obey God. His action would not have meant anything if it had not come from his faith in God since it is impossible to please God without faith (Heb 11.6).

 

Psalm 106:29 Thus they provoked him to anger with their inventions: and the plague brake in upon them.
30 Then stood up Phinehas, and executed judgment: and so the plague was stayed.
31 And that was counted unto him for righteousness unto all generations for evermore.

"That was counted"

Because Phinehas executed judgement is what God said

 

Compare Hebrews Chapter 11, a chapter about people who acted upon their faith, just as did Phinehas.