The article ''N. Va. Diocese Joins Sex Education Opposition'' {Metro, Dec. 11} is an excellent example of a double message. Not long ago Catholic Charities of the Arlington Diocese offered an outstanding family communications/values-based sex education program. The participant families were unanimous in their praise.

The same Diocese of Arlington leadership and church group that ''trashed'' this excellent program now is out to destroy the sex education program offered in our public schools. Where was Bishop Keating and his so-called advocates of value-based sex education when the Catholic Charities program was going down in flames? I'll tell you. They were leading the charge against it. I know, I was on the Catholic Charities Board when the program was shut down.

Based on the dismal track record of church leadership on this issue, shouldn't we be asking when the church is going to start focusing on the needs and the well being of its young people. The fact is that with skyrocketing teen pregnancy rates, abortions etc., this is too important an issue for our young people to be left to learn about in the streets. The church has an obligation to its young to be more positive, constructive, sensitive and responsive to their needs. JOHN E. HOREJSI Vienna