In the 70 years since Vladimir Lenin rose to power in the Soviet Union, some 6,000 books have been banned or restricted there. They include political books, works of fiction, and Christian and Moslem holy books.

Many of the affected books were available for the exclusive use of specialists. Others, like the Koran and the Bible, could be imported in small quantities, but were confiscated at the border if they were not accompanied by official documents.Now things are changing. A Soviet censorship review committee has examined 4,000 of the banned books and lifted restrictions on 3,500.

Those still banned include some termed "too easily misunderstood by a politically immature audience."

Among the books back in circulation are the memoirs of Alexander Kerensky, who was overthrown by Lenin; Gen. Anton Denikin, who led the White Army against Lenin in 1918-20; and a host books by politicians purged by Josef Stalin.

More significantly, the review committee has made it legal for people abroad to send Christian and Moslem holy books to believers in the Soviet Union. Religious journals, too, can now be imported if they are judged sufficiently "solemn."

Vladimir Solodin, head of the committee that examined the restricted books, said the new rules are part of Soviet leader Mikhail Gorbachev's attempt to lift the shroud on Soviet history. But the new rules will do far more than that.

For religious believers in the Soviet Union who have long complained of the unavailabily of Russian-language Bibles and Korans, a new era of light has begun. To Christians, who will mark the 1,000th anniversity of Christianity in Russia this June, there could be few more welcome gifts.