The Baptist Joint Committee on Public Affairs filed a brief with the U.S. Supreme Court last week arguing that religious organizations should not use government funds to fight teen-age pregnancy.

In a challenge to the 1981 Adolescent Family Life Act, the Baptist body argued that the law violates the Constitution by providing federal financing to religious groups in their battles against sexual promiscuity and abortion.

Under the law, also called the Teen Chastity Act, Congress provided the financing "to promote self-discipline and other prudent approaches to the problem of adolescent premarital sexual relations, including adolescent pregnancy" and to encourage adoption rather than abortion.

The disputed law also requires all recipients of the funds to seek participation by religious groups in administering their programs.

Last year the U.S. District Court for the District of Columbia ruled that the law, as originally written, violated the First Amendment, which prohibits moves to establish religion.

Subsequently however, the same court held that the section of the law financing religious groups could be severed from its other provisions, thereby salvaging that part of the law. Financing for all groups covered by the law, including religious organizations, has continued uninterrupted under a stay issued in August by Chief Justice William H. Rehnquist.

While commending efforts to combat sexual promiscuity, the Baptist brief argues that "it is impossible for religious organizations to teach sexual morality without consciously or unconsciously promoting religion." Any grant program that subsidizes such teaching "is constitutionally impermissible," it adds.

The American Jewish Committee and Americans United for Separation of Church and State joined the Baptist Joint Committee in filing the brief.