Many times, Christians note Augustine of Hippo’s assertion that we should “plunder the Egyptians,” or in other words, we should borrow the scholarship of the world around us. Yet, as inspiring as Augustine’s ideas are on this subject, he is also a negative example of what can happen when we borrow unbelieving scholarship uncritically. Augustine borrowed very heavily from the philosophical ideas of Plato, and this had a negative affect both on his theology and on his method of interpreting the Scriptures.
As noted in our work on the Tragedy of Compromise, my view is that we need to stay aware of, and reject, ideas that require assumptions that do not accord with the Christian faith. I base this on something I call the “Unified Fields Theory of Apologetics”, which is a statement of systematic theology that I discussed in a brief form, in an article on our more technical site. (Systematic theology is an orderly, rational account of the Christian faith and beliefs along with the attempt to answer the religious questions I’ve noted elsewhere). That article can be found here: http://apologiafides.wordpress.com/2014/06/27/squaring-the-circle/.
I am not suggesting that we ignore actual scientific data or that we ignore studies by those outside of the faith. Paul himself quoted from pagan poets and borrowed language from the stoics. One of the first intellectual challenges for the young Christian faith was to communicate its ideas to those outside of the faith.
Psychology does have some actual benefits. There are scientific elements within psychology that may be beneficial. For example, studies of the effects of sleep deprivation on human beings and certain statistical studies, (e.g. a certain percentage of the population will react to a given stimuli in a given way) are both valuable. Counselors may use counseling techniques in a manner similar to the way a preacher learns and uses the art of effective or persuasive speaking and writing.
I am suggesting that we need to filter psychology because much of what passes for psychology is religion, in disguise.