In reality, religious people have been behind some of our greatest advances, from the abolishment of slavery to the fight against racial discrimination. And Christians have built thousands of hospitals, schools and orphanages throughout the world.
But you're right when you say Christians often oppose other movements, including some you probably would endorse. They do so because they believe any society (including ours) is only as strong as its moral and spiritual foundations -- and if those foundations are destroyed, society itself will eventually crumble.
Why is this? The reason is because God knows that when we neglect what's right and wrong, we'll end up destroying ourselves. You say we ought to be free to do anything we want to do, "as long as we aren't hurting anyone." But even if we don't hurt anyone else, we still hurt ourselves if we ignore what's right or wrong. And when we hurt ourselves, we eventually hurt others.
Don't be misled; don't end up taking a path in life you'll only regret later. Instead, I challenge you to examine your life in light of God's truth. God loves you; He loves you so much that He doesn't want you to destroy yourself by ignoring His moral truths. Living for yourself is a dead-end road, but living for Christ brings joy and peace. Jesus' words are for you: "I have come that they may have life, and have it to the full" (John 10:10).