Understand it is for our sake!

Ps 136 is a great example of how scripture cannot just be read or verses plucked out for separate use unless you take into account the whole context, people, places, and purpose for the writing. Check out Ps 136 v 10. "Killed the firstborn of Egypt, his LOVE endures forever"...now without knowing the context of the writing, I'd say that the killing of someone does not really show love. In Ps 139, the psalmist writes about God being all knowing, all powerful, and everywhere. In that case, why do we need to pray? He should already know! HE DOES! We don't pray for Him to work, He is not a genie we release from a lamp. No, we pray to show our reliance and devotion. To get ourselves out of the way to focus on God. The final verses are key, Ps 139 v 23-24. Search me...know me.