EDIT: I added "humanitarism" to the title for a lack of a better word - for me it's clear that Jesus teaching was far more radical than even today's humanitarism (one of the consequences is that hardly anyone faithfully follows his teaching today and Christian clergy doesn't push it).
The New Testament was written no later than 2nd century AD. From my understanding, the world during that time was harsh/cruel/ruthless from today's perspective, but it was completely natural for people living at that time. Surely the Greeks and Romans had pretty advanced statehood, including democracy. But that didn't mean that present day values such as compassion, mercy, forgiveness, unconditional love etc. were values for anybody. Instead, they had slavery, eye for an eye, torture, stoning, gladiators, revenges, cult of money - basically a value system completely different from the Christian one. The Old Testament doesn't go nearly as far as the New Testament in that regard either.
Now, it is rather known fact that many people who call themselves Christians had done all those bad things and hadn't followed Christ's teaching for many centuries afterwards. But that's not the point.
The point is: has someone else from that era or others come up with ideas similar to those of the Christ? 8 blessings, "turn the other cheek", giving everything to the poor, "cast the first stone", "love your neighbour" etc. Aren't such ideas very revolutionary for that period? Is there a known case of someone promoting such values before Jesus or after him but with no prior knowledge of Christianity?