In the Aaronic Benediction, the Lord says to us, "The LORD make His face to shine on you."Why do I want His face to shine on me? Well, the Bible says a lot about "shine." Shining has to do with becoming light, illuminating like daybreak when the brightness of the sun pierces the darkness. The word for shine used in this blessing has to do with luminescence, as when light glows through from within, as an inner light.
This idea of shining – "The LORD make His face to shine upon you" – also has something to do with divine approval. In His presence we have God's approval and He is pleased with who we are and what we are and what's been going on. That which is dross should burn away in His presence. In Daniel 9, Daniel implores the Lord to lift up His face and shine on His sanctuary and reverse the desolate condition of Jerusalem. He says, "Lord, shine on Jerusalem again. Shine Your face on Jerusalem. Show Your face in the midst of this situation."
So when you recite this Aaronic Benediction, "The LORD make His face to shine on you," you are asking God to come and bring His very presence, because where God is, there is light. Light symbolizes life and prosperity. To see the light is to be born – the light of life – to be alive.
"The LORD make His face to shine on you – is also to light you up, to bring understanding. It is associated with life, salvation, with wisdom and understanding. Look up the word "light," and you will find numerous examples of this, e.g. God will give "light to the nations," "The LORD is my light and my salvation." Where there is light, there is the LORD.