New Revised Standard Version
and know his will and determine what is best because you are instructed in the law,

Contemporary English Version
By reading the Scriptures you learn how God wants you to behave, and you discover what is right.

New American Bible
and know his will and are able to discern what is important since you are instructed from the law,

Douay-Rheims Bible
And knowest his will and approvest the more profitable things, being instructed by the law:

And knowest his will and approvest the more profitable things, being instructed by the law:

knowest.

Deuteronomy 4:8 For what other nation is there so renowned that hath ceremonies, and just judgments, and all the law, which I will set forth this day before our eyes?

Nehemiah 9:13,14 Thou camest down also to mount Sinai, and didst speak with them from heaven, and thou gavest them right judgments, and the law of truth, ceremonies, and good precepts. . . .

Psalm 147:19,20 Who declareth his word to Jacob: his justices and his judgments to Israel. . . .

Luke 12:47 And that servant, who knew the will of his lord and prepared not himself and did not according to his will, shall be beaten with many stripes.

John 13:17 If you know these things, you shall be blessed if you do them.

1 Corinthians 8:1,2 Now concerning those things that are sacrificed to idols: we know we all have knowledge. Knowledge puffeth up: but charity edifieth. . . .

James 4:17 To him therefore who knoweth to do good and doth it not, to him it is sin.

Philippians 1:10 That you may approve the better things: that you may be sincere and without offence unto the day of Christ:

*marg:

1 Thessalonians 5:21 But prove all things: hold fast that which is good.

Hebrews 5:14 But strong meat is for the perfect: for them who by custom have their senses exercised to the discerning of good and evil.

being instructed.

Romans 15:4 For what things soever were written were written for our learning: that, through patience and the comfort of the scriptures, we might have hope.

Psalm 19:8 The justices of the Lord are right, rejoicing hearts: the commandment of the Lord is lightsome, enlightening the eyes.

Psalm 119:98-100,104,105,130 Through thy commandment, thou hast made me wiser than my enemies: for it is ever with me. . . .

Proverbs 6:23 That they may keep thee from the evil woman, and from the flattering tongue of the stranger.

2 Timothy 3:15-17 And because from thy infancy thou hast known the holy scriptures which can instruct thee to salvation by the faith which is in Christ Jesus. . . .