There is nothing wrong with using a Strong's Concordance - as it gives a basic definition and word range/usage in the KJV Bible. Of course, each definition must be taken in context of the passage and English word studies are useful to show how God uses the word throughout the Bible.

What James is stating is that we must be in right standing with God (ie. righteous in the way we are living) in order to have our prayers answered. Of course, he is writing to believers who already have Christ's righteousness because of their personal faith in the Lord Jesus Christ.