"People will listen to you when they know you care for them". Corollary: "People don't care what you know until they know that you care".
It seems to me that these two statements have often been used in various kinds of settings, including that of ministry. I would just like to analyze these two statements here.
These two statements, of course, are statements regarding the psychological makeup of Man in general. It concentrates on how people most probably react when interacting with others. Scripture does not explicitly says anything about this subject matter, with Scripture only telling us to speak the truth in love (In Eph. 4:15 explicitly and others more implicitly). It does not tell us the psychological responses of the people if this is or isn't followed, which is what these two statements tries to do.
First of all, I would first like to say that as a Christian, I hold to the doctrine of Sola Scriptura or Scripture alone. This may seem to be a trivial thing to note, but as experience have shown to me, there are Christians out there who seem to compartmentalize their knowledge and thus accept Psychology uncritically, even not bringing Scripture to bear on this discipline. Indeed, there may be Christians out there who subconsciously accept Psychology even as the 67th book of the Bible. This is not only unbiblical, it is a sin against the LORD God as revealed in His Word, who is incarnated as the Lord Jesus Christ. For such people, I sincerely urge you to repent and return to God as revealed in His Word.
Back to the issue at hand, we can see that Scripture does not tell us the psychological responses of people when they are told the truth, whether it is told in love or not. Given that Scripture just maintain that we are to speak the truth in love (which I am currently doing a blog series on), the seemingly correct thing to do would just be to ignore the issue altogether and just do what Christ asked us to do. However, depending on how one understand these two statements, there may be further implications which are unbiblical.
These two statements could be said to mean from its surface level generic reading that a person tend to listen better to another person who cares about him/her than from a person who doesn't, and that most people tend not to listen to you unless they know that you care for them. Such an understanding would thus seem to be correct, as we can see from our daily experiences. If that is all these statements mean, then the statements would be correct, at least from our generic experiences.
However, a deeper look into these statements do not suggest that this is all there is in the statements. The statements are by necessity man-centered since they are trying to describe Man's psychology. This may well be good for application in more secular-minded areas, but it will encounter problems when people often try to apply it in Christian contexts. In such contexts, such anthropocentrism could well have a chilling influence in the way for example ministry is done. What I mean by this is that such statements could lead to people in the ministry placing undue emphasis on loving people and "accepting them just as they are", at the expense of proclaiming the Truth to them out of fear that they might be offended. This is especially so since the sentences seem to suggest that Man may be more well disposed to listen to you if you care for them whereas the Gospel itself is an offence to the natural Man (1 Cor. 2:14) and thus it make little difference salvifically with regards to the Gospel unless the Holy Spirit regenerates the heart of the unbeliever. Such a scenario may not oftentimes be the case, but it is a potential problem nonetheless. When coupled with an Arminian (or even Pelagian) outlook on salvation and the nature of Man, the risk increases manifold as all variants of Arminianism and Pelagianism essentially deny in part or the whole the absolute sovereignty of God in salvation. Therefore, consistent adherents of these heresies would dispute the interpretation and application of 1 Cor. 2:14 and in fact the entire passage of 1 Cor. 1:18 - 2:14, believing that Man plays a pivotal role in salvation, though it may be very minor as in Arminianism or the most important role as in Pelagianism. This would leave them wide open to such an undue emphasis, if it haven't entered already, which would result in all sorts of nonsense like the Seeker-sensitive movement and the Purpose Driven movement, or the generic symptom known as amusing the goats.
From the passage of 1 Cor. 1:18 - 2:14, it can already be seen that it is not necessary nor sufficient that caring for people would result in people wanting to know what you know or even be predisposed to such. This by itself should bring a lot of these nonsense entertainment that is going around so-called Evangelicalism to a stop. That it doesn't do so speaks volume of the fidelity of Evangelicalism as a movement to God as revealed in His Word.
Back to the issue of these two statements, I think that these two statements are genuinely well-meaning. However, due to their inherent anthropocentrism, they should not be used in Christian settings. Perhaps a biblical focus on speaking the truth in love BECAUSE of God's decree and love for us instead of the perceived pragmatic benefits/ disadvantages that may occur would be much better by far.