This is good information to warn people in the ways of man. Also praying for discernment gives one unction of the Holy Spirit  to be given knowing, regardless of the external appearance and even the best of behaviors. He indeed can help one to separate the wheat from the chaff. Also to warn one from danger/harm. We have the natural component of knowledge, as presented in the above information which is certainly useful. There is then also the supernatural component which can preserve us from deception. The challenge is to heed the signs and act accordingly. Especially, as in the info you presented, that one is in the "honeymoon" phase of a relationship and wants so much to buy into the "love" being offered. Narcissistic psychopaths excel at this. Extremely dangerous. Couple that with position of authority and certain agendas: these present a real and present danger to US.