Think is first written of in Gen.40:14 Where Joseph's mouth was moving, but it was the Words of the Lord, "But think on me when it shall be well with thee." The Lord has always admonished us to control our thoughts, and be careful of what goes into our computers; eventually what goes in will manifest itself through speech, or actions.
The Nehemiah request in Neh.5:19 "Think upon me, my God". Jer.29:11 The Lord states "For I know the thoughts that I think toward you." Immanuel [God in the flesh] was constantly calling people's hands concerning what they were thinking. Anytime the Lord ask what we are thinking, it is a rhetorical question.
There are far more distractions in the world now, than 40 yrs. ago; it will continue to worsen. These prove to be only divert our attention away from what is important. The Great Commandment must be met. What we think will immediately come out when surprised or shocked.
The Apostle Paul states "I think myself happy." We must control what we think. Think = consider, desire, intend. To separate mentally. To mark, reckon thoroughly. To deliberate, ponder. We can Not be double-minded, luke-warm, or a reed shaking in the wind, once we dial in what we think.
Rom.12:3 "Think soberly." Ephes. 3:20 "Above all that we can ask or think." Phil4:8 What to think on. For those that are able to discern the signs of the times, it is important to think, and think cleanly. Christ yoke is light, and easy, and we should not add, or allow others to add manure to our back-packs. This is the time to Think - or - Sink.