The call of a Christian can be a difficult tight rope at times. We are called to be kind, but not naive. We are called to speak the truth, but to speak it with love. Sometimes the truth doesn't seem very loving, and even our best efforts to do so may not be taken that way from the person receiving it. 

Our confidence in ourselves to balance this should be weak, because in ourselves we will struggle to juggle the two. But the Holy Spirit has equipped us to build up the body of Christ, so our confidence should be in Him to guide us through the challenges. When we don't know what to do, the answer is simple: Rely on Him!