Getting light means that the Holy Spirit shows you something. For example, you can get light over your own sin and see that you are selfish, proud, etc. It can also mean getting more insight (revelation) in the Word of God and His work in those who follow Him, and His promises for them. (Psalm 118:27; Psalm 119:130; John 1:4-5; John 3:19-21; 2 Corinthians 4:6; Ephesians 1:17-18.)