try to find out what pleases the Lord Ephesians 5:10
The scripture you asked about does not mean what it seems to. Similarly, why the translators of the NASB (my favorite translation because of its accuracy) used the phrase "trying to learn what is pleasing to the Lord" is beyond me. That phrase "trying to learn" is from a Greek word that means: test, examine; interpret, discern, discover; approve; prove, demonstrate. In context, it fits quite well. When you read Paul's letters, for example, make sure you notice how he always establishes the reality of who the believers really are. In Ephesians 5, Paul is addressing the believers as "beloved children" (v1), "saints" (v3), NOT "sons of disobedience" (v6&7), "formerly darkness, but NOW you are light in the Lord" (v8). His admonition was for the believers to live like the believers they were.
On every side it is being suggested that we must play by the rules of the world. But we have been delivered from the old and have been made new. That is why it rakes against your very being and desires to destroy your sense of the joy that is part of your heritage. Take a look at the flow of Paul's thought without the parenthesis (v9) and using a literal wording (v10). "...walk as children of light proving what is pleasing to the Lord". Paul's message to the Ephesians is exactly what you need to hear, for as a child of light there is only one legitimate mode of operation - and that is to SEE YOURSELF AS THE CHILD OF LIGHT HE MADE YOU AND TO LIVE LIKE WHO YOU REALLY ARE! This is how you discover, or prove, or discern what is pleasing to the Lord.
If you read the next few verses with our miraculous change from darkness to light in mind you'll hear Paul calling attention to our need to always distinguish the difference. He quotes an Old Testament verse and ties it in as calling to us to "Wake up!" and goes on to warn the believers not to be foolish, but as WISE MEN in how we walk ... and to understand the will of the Lord. And what is the will of the Lord? It's not some hidden or difficult agenda God wants you to figure out, it's the simple reality of knowing God's desire, which is Christ as being your life ... the same thing he had written about from the beginning of the letter.