The King James Version of James 1:17 states - 

"Every good gift and every perfect gift is from above and cometh down from the Father of lights, with whom is no variableness, neither shadow of turning."

The fact that we have a wonderful, divine, heavenly Father that desires to give us gifts is heartwarming, mind-blowing and encouraging to the soul all at once. However, there is a particular gift that "the Father of lights" gives in which He expects us to give or share in response.

God is called "the Father of lights" which means "the lights" are His offspring. In His sermon on the mount, Jesus described His followers as light and instructed them to shine for God's glory.

"You are the light of the world. A town built on a hill cannot be hidden. Neither do people light a lamp and put it under a bowl. Instead they put it on its stand, and it gives light to everyone in the house. In the same way, let your light shine before others, that they may see your good deeds and glorify your Father in heaven." (Matthew 5:14-16)

Notice the importance of the light. God has empowered true believers with His Holy Spirit to be the light of the world. Christ shows scale by starting with a town on a hill then light hidden under a bowl within a house. He also shows no societal boundaries by displaying His light in public on a hilltop town and in private within a house needing luminance.

Paul adds to this idea when he said, "To them God has chosen to make known among the Gentiles the glorious riches of this mystery, which is Christ in you, the hope of glory." (Colossians 1:27) The key is "no variableness".

In the main scripture of study for today, James 1:17, God - the giver of good and perfect gifts and Father of lights has "no variableness". God's light, His perfect nature does not change. His brilliance does not increase or decrease, believers have just not discovered the next wonderful side of God yet.

God cannot improve, but we will always have room for improvement. Still, as a work in progress, I believe the notion of consistency in Godly nature for Christians is important. 
Believers ought to strive for consistent harmony between The Word of God and the light they shine just as with The Lord there is "no variableness, neither shadow of turning".