Religion can not dictate that you should get married to someone within the same religion or within the same sub-sect of the religion. Religion can not define the age at which you have to get married. Religion can not thrust upon you the desirable terms and conditions for marriage.
But does it mean that religion should absolutely have no say in nuptial matters? No. Religion can always guide you on what is desirable in a marital bond; religion may also suggest what the ideal of marriage is; religion can warn you of what is not desirable in a marital relationship. But it is finally up to the individuals to heed to the recommendations, suggestions, guidance and warnings that religion offers or ignore them to suit their own convenience.
Religion can not dictate terms like a strict and stubborn father or a school teacher; but religion can always counsel you like a good and trusted friend. When a friend gives you some advice or warning in the matter of marriage, you will be quite inclined to give a patient listening; keeping the final decision-making power within you, you will definitely be giving due weightage to the counsel. Likewise, in the interest of individual’s mental peace, family relationship, social norms of morality and and social harmony, it is always better to understand what religion says in the matter of marriage and give due weightage to it.
In the Hindu religious scripture Katha Upanishad, two Sanskrit words are used in the matter of choice : “Preyas” and “Shreyas”.
What you choose based on attractiveness rather than goodness, based on short term benefits and pleasures over long term – such a choice is classified as “preyas”. On the other hand, a choice made based on goodness rather than transient pleasantness and long term benefits over short term attractions is known as “shreyas”. People generally have the tendency to fall for “preyas” rather than “shreyas”, but it is wise who prefer “shreyas” to “preyas”.
Religions mostly guide you on what is “shreyas” for you and they warn you not to fall for “preyas”. Every religion carries fair amounts of wisdom of some great religious masters, whose concern for the welfare of the society can not be belittled. Of course, every religion, over a period of time gathers some superstitions, dogmas and the counsels of misguided interpreters of the religious principles. By ignoring the dross, and heeding to the time tested principles and values, the individual as well as the society by and large gets benefited by the religious guidelines.
Practically all major religions recommend one man getting wedded to one wife for the entire life; sexual promiscuity and seeking relationships outside the framework of marriage are never encouraged. Homosexuality is never encouraged in any religion. Parental commitment to rearing the children and making them responsible citizens for the future is deemed as a duty in most of the religions.
It can be seen that most of these suggestions from religions are aimed at abetting “shreyas” to the individuals and society. Those who are opposed to any form of disciplining, those who want to lead a life of enjoying privileges without shouldering responsibilities, those who want to live for the short term merriment at the cost of long term peace and tranquility may perhaps not like the religion even to counsel what is “shreyas” to them.
It is such people who normally take religious guidelines as “definitions” or “dictums” and protest vociferously that religion has no right to interfere in their personal choice and freedom.