Just because we do things, say things behind closed doors thinking that nobody will ever catch us doesn't mean God doesn't see what we're doing. We can fool everyone else but can't hide from Him.
"15 For we do not have a high priest who is unable to empathize with our weaknesses, but we have one who has been tempted in every way, just as we are—yet he did not sin. 16 Let us then approach God’s throne of grace with confidence, so that we may receive mercy and find grace to help us in our time of need." Hebrews 4:15-16
Like I said in my previous post, Jesus lived among us as a human being tempted in every way just like we are every day, BUT he did not sin. Verse 16 then encourages us to come before Him because God knows we are sinful beings- that's why He gives us grace and mercy.
