Deuteronomy 13:1-4–“If a prophet or a dreamer of dreams arises among you and gives you a sign or a wonder, 2 and the sign or wonder that he tells you comes to pass, and if he says, ‘Let us go after other gods,’ which you have not known, ‘and let us serve them,’ 3 you shall not listen to the words of that prophet or that dreamer of dreams. For the Lord your God is testing you, to know whether you love the Lord your God with all your heart and with all your soul. 
There are situations in life that test what we will do “to get over”, with no regard to whether it is morally right or not.  Not growing up in a Christian home, we just called that “hustling people”.  We didn’t care whether it was right or not, we wanted to preserve ourselves, so we always made out better in the deal.  Essentially we did what “worked”.  That would be the definition of living an “expedient life”.
If you think about how much “expediency” plagues our country in so many different agendas, you realize we naturally only care if things work out for us or not.  Think political leaders, who must cater to what works for the people to vote for them.  If things seem to workout best for us, than they get our vote.  Even Christian families can fall victim to what is “expedient”, and not necessarily what is right and true. Because what is best to us may not be Truth or God, but results and benefits…
This was the premise of God’s passage to the children of Israel.  Not to trust in a prophet or dreamer, who brings about signs and wonders, that work for our good. Moving them from faith in God and His truth, to what works out best for their agenda. Proving they aren’t worshiping God, but whatever and whoever “works out” better for them!
To live by the ethic of “what works”, instead of faith in God, will cause us to have the desire to exchange not only methods of living, but people!  So if my spouse no longer “works for me” than I exchange them for who will.  Sadly real faith and love can never develop, because we’ve learned how to “hustle for what works”, in exchange for Christ and His ways…
In His Love, Ld