Congress may soon call on religious institutions ranging from summer camps to charities to declare up-front whether they are unwilling to hire gay employees. A bill that, if passed, would become the first federal law to prohibit employment discrimination against gays contains a broad exemption for religious organizations. But to qualify for that exemption, religious groups would have to declare "which of its religious tenets are significant" and must be adhered to by employees. Lawyers say this requirement could put pressure on religious organizations to state a doctrinal prohibition against homosexuality in order to continue to legally exclude gay job...