When we speak out about the gospel, we view it as ultimately the most kind thing we can do. We are bringing light to darkness and offering hope to the hopeless. We are speaking the only truth that can save a person's soul. In spite the good reality of the gospel, it is often perceived as quite the opposite.
One reason the gospel is offensive is because it is opposes today's climate of pluralism. This is the second barrier to evangelizing post-moderns.
Your post-modern coworkers have met all sorts of people of different religions. Their Buddhist, Hindu, Muslim and Jewish acquaintances have been some of the most kind, sincere and generally pleasant people they have met. There seems to be a mutual respect, and relishing diversity seems altogether reasonable. After all, it seems to have worked for them.
Now we bring the gospel. We explain that there is only one true and living God. We explain that we have all rebelled against God and deserve His punishment. Furthermore, we explain that Christ is the only way to be reconciled to God.
Then they ask, "So do you mean that anyone who doesn't believe in your Jesus is going to hell? You believe that you're right and all other religions are wrong?" Though you might try to say "yes" as gently as you can, the substance of the answer is in a certain sense quite harsh.
Another aspect of this problem of pluralism relates to cultural diversity. Maybe you invite your friend to church. During the course of the sermon, the pastor brings the hammer down on homosexuality and promiscuousness. Your friend finds this offensive and promises to himself never to go to a Christian church again. Why the offense? Your friend knows several homosexuals, and they are nice people. Most of his friends are sexually promiscuous, and they too are nice people.
When we tell someone that all these nice people are, in a sense, on God's bad list, we ourselves seem unkind at best, if not outright hateful.
How do we evangelize people without compromising the truth? Certainly, rounding off the sharp edges of the gospel is not the answer.