“…now you are light in the Lord…”  Ephesians 5:8
 
‘now you are…’ that of course indicates that there was  time when you were not.  It, also, indicates that what took place was completely life changing.  It ended one thing and began another and you will never be the same again. I am, of curse, speaking of the new birth from above.
 
“Jesus answered him, I assure you, most solemnly I tell you, that unless a person is born again (anew, from above), he cannot even see (know, be acquainted with, and experience) the kingdom of God.”  John 3:3  The Amplified Bible
 
“Therefore, if any person is [engrafted] in Christ (the Messiah) he is a new creation (a new creature altogether); the old [previous moral and spiritual condition] has passed away.  Behold, the fresh and new has come!”
2 Corinthians 5:17  The Amplified Bible
 
“He made Him who knew no sin to be sin on our behalf, that we might become the righteousness of God in Him.”  
2 Corinthians 5:21
 
The first part of our beginning verse states, 
“For you were formerly darkness, but…”  You were, but now you are!  
The rest of the verse and verses 9-10 say,
“…walk as children of light (for the fruit of the light consists in all goodness and righteousness and truth), trying to learn what is pleasing to the Lord.”
 
We do not automatically know how to walk as children of light.  This a process that God takes us through.  We are so used to doing things our own way, wanting to be in charge of everything involving ourselves AND others, that it takes our Heavenly Father to teach us.  
 
Child training is what is meant by ‘discipline’ in Hebrews 12.  It is Love Himself who does the child training.  To know God is to know that all His discipline is because He loves us.  Scripture makes this very clear.  I urge you to read Hebrews 12:1-13, but let’s look at just a few of these verses.
 
“My son, do not regard lightly the discipline of the Lord, nor faint when you are reproved by Him; for those whom the Lord loves He disciplines, and scourges every son whom He receives.”  
Vs. 5b-6
 
Notice ‘whom He loves’ and ‘every son whom He receives’.  He has to teach everyone of us.  None of us know the ways of God nor can we unless He teaches us.  And it should be our heart’s greatest desire to know His ways and His will for our lives.
 
“It is for discipline that you endure; God deals with you as with sons; for what son is there whom his father does not discipline?  But if you are without discipline, of which all have become partakers, then you are illegitimate children and not sons.”  Vs. 7-8
(Did you catch that ‘all have become partakers?’  That leaves no place for the ‘why me, God?’ that is so often asked when there are dealings in our lives.)
 
“Furthermore, we had earthly fathers to discipline us, and we respected them; shall we not much rather be subject to the Father of spirits, and live?
For they disciplined us for a short time as seemed best to them, but He disciplines us for our good that we may share His holiness.”  Vs. 9-10
(Imagine Almighty God wanting to share His holiness with man!  How awesome.)
 
“All discipline for the moment seems not to be joyful, but sorrowful; YET to those who have been trained by it, afterwards it yield the peaceful fruit of righteousness.”  
Vs. 11
 
This brings us back to Ephesians 5:9, where righteousness is listed with goodness and truth as the fruit of light.  “…the fruit of the light consists in all goodness and righteousness and truth.”
 
It is God who is in control of our lives and nothing comes to us that He does not intend it for our good.  So let us yield to Him this life that He has given us, that He may be glorified in it and through it now and forever.  Amen 
 
May you know His abundant blessing this day!