Am I obligated to only buy soda?
18th century english was filled with this construction, {reason}, {statement}. For comparison, see Rhode Island's constitution, Article I, Section 20- "The liberty of the press being essential to the security of freedom in a state, any person may publish sentiments on any subject..".
You seem to think that the bill of rights somehow limits rights to certain purposes, or 'grants' rights to people. It doesn't. The preamble is a great place to start:
[div class='excerpt']The Conventions of a number of the States having at the time of their adopting the Constitution, expressed a desire, in order to prevent misconstruction or abuse of its powers, that further declaratory and restrictive clauses should be added: And as extending the ground of public confidence in the Government, will best insure the beneficent ends of its institution.
The Bill of Rights was intended as a 'the government shall not' document- "to prevent misconstruction or abuse of its powers"- not a 'the people can' document. If the Bill of Rights were a listing of all a person's rights, there would be no need for the ninth and tenth amendments ("The enumeration in the Constitution, of certain rights, shall not be construed to deny or disparage others retained by the people." and "The powers not delegated to the United States by the Constitution, nor prohibited by it to the States, are reserved to the States respectively, or to the people." respectively.)
You should read other cases such as US v Cruikshank ("This right is not a right granted by the Constitution . . . neither is it in any manner dependent upon that instrument for its existence."