I take a different perspective and say a lot of the blame for this ridicule of Christianity has to go to Christians themselves, who by their beliefs have made Christianity a laughing stock. When God talks about the decline of his people, does he blame the outside world or does he blame the people themselves? The world isn't making the church a laughing stock, the church itself is.
Today's Christians have so watered down the gospel to conform to the world's ideas of discipline, morality and wisdom that it is unrecognizable as anything but hypocritical and something to deride. They bend over backwards to accept ridiculous views and personal opinions of book authors as legitimate Christianity. Even more, that the clergy and tradition carries special weight over and above the Bible record. To me it seems that they are more trying to get Christians to break free of God's authority, and when that happens then God himself will laugh.
Ps 2:2 The kings of the earth set themselves, and the rulers take counsel together, against the LORD, and against his anointed, saying,
3 Let us break their bands asunder, and cast away their cords from us.
4 He that sitteth in the heavens shall laugh: the Lord shall have them in derision.
Is it no wonder the world laughs when the church is in derision. These modern kings of the earth have managed to make their church teachings completely irrelevant to modern society, and acceptable only when they teach social values and acceptances that are laughable and absurd in the real church. Like Homosexuality, Abortions, Women Priests and liberal philosophies. When we think of ourselves as progressive by accepting sexual immorality, divorce and irresponsibility, what we do is make the church nothing more than a hippie commune without the Kumbaya, colorful clothes and long hair. Shall He that sitteth in the heavens not laugh?