When in Rome do as the Romans do. Most of us accept this without realizing that it is an argument against objective morality. To be consistent, if we accept this argument we should also accept the argument that every Pakistani (if they accept the value of their community and wish to be a member of it) should be forced to accept their Muslim culture. So, for example, in the Muslim culture it is right to be flogged for becoming a Christian. This is the one of the laws that have enabled the Muslim culture to flourish, and, for its continued flourishing, its laws need to be upheld .
And everybody in that culture, in that community by choice, should accept the rules of that community. In our western culture we feel that such a punishment is abhorrent and we, certainly Christians, and maybe a lot of atheists, think we have the right of objective morality on our side. Basically we think this because we think that the majority of right-minded people think the same way as we do, and christians extend the source of this thought to god. However to think that the majority is right is also a flawed argument. Once we understand that there may be more and greater intelligent life in the universe than our one we start to see that our majority may not be the correct one. Thus a great intelligent life may agree that it is acceptable to harshly punish to keep your own society together.