'Yet' in the Bible

You ask [God for something] and do not receive it, because you ask with wrong motives [out of selfishness or with an unrighteous agenda], so that [when you get what you want] you may spend it on your [hedonistic] desires.

Yet you do not know [the least thing] about what may happen in your life tomorrow. [What is secure in your life?] You are merely a vapor [like a puff of smoke or a wisp of steam from a cooking pot] that is visible for a little while and then vanishes [into thin air].