This doesn't mean truth should be reduced to utility (i.e. only good if it's useful). But look at the implications of what Jesus said: "You will know the truth, and the truth will set you free." HOW will it set me free? That's what I need to know! "What's in it for me?"
And that's what people want to know when we share with them the Gospel. Our audience may not be asking this question consciously, but they are asking it. We long for freedom and happiness. And that makes us long for truth, often not even realizing that it's the truth we're after.
So if we are to speak the truth in love, the Good News of Jesus Christ must reach boldly into the cultural milieu of our audience, and it has to confront their way of life not with antagonism but as a path to the freedom we all long for. They must come to understand that our sinful habits and lifestyles stand in opposition to our freedom, not the Gospel, not the truth.
In advertising, this is actually called the WIIFM Principle. It means tailoring the message (not watering it down!) to fit the needs of the audience. It means knowing our audience personally, so that our proclamation of the Gospel might be framed around their particular problems and questions. It means providing solutions.
And it also means, once again, the faith must never be reduced to a list of propositions about God and sin and grace and heaven. If it's not fueling a transformative relationship with Christ, the knowledge of doctrine bears no real fruit. So (in the words of advertisers), we sell the benefits above the features. We teach the truth boldly, of course, but with the WIIFM Principle in mind. And this is no gimmick. The benefits of God's merciful love are great indeed.