Omnipresence of God
Proverbs regarding the all-seeing nature of God
For the ways of a person are in front of the LORD's eyes, and the LORD weighs all that person's paths. Prov. 5:21 (read whole chapter)
The eyes of the LORD are in every place, keeping watch on those who are evil and those who are good. Prov. 15:3 (read whole chapter)
The name of the LORD is like a strong tower; the righteous person runs to it and is set safely on high. Prov. 18:10 (read whole chapter)
All of a person's ways seem right in his own opinion, but the LORD evaluates the motives. Prov. 21:2 (read whole chapter)