President Mohammed Zia ul-Haq, a devout Moslem, has said the cure for Pakistan's problems is to turn it into a full Islamic state.

So under government orders school girls and women teachers last week began wearing full head coverings as part of their uniforms and boys have traded their blue blazers and old school ties -- a holdover from the British Raj -- for the Pakistani national dress of long loose shirts and baggy trousers.

Arabic has become a required language in school to make it easier for people to read the Koran in its original language. Every speech by Zia in recent weeks seemed to focus on Islamization to the exclusion of such national problems as a weak economy and the estimated 80,000 Soviet troops across Pakistan's northwestern border in Afghanistan.

But instead of bringing the country together, Islamization may be further dividing it.

One of the most divisive moves in the program came in July when Zia announced that the government would collect a 2.5 percent tax on all fixed deposit bank accounts. This hit middle -class Pakistanis the heaviest since they have their savings in banks while the wealthier invest their money in real estate, according to Pakistanis.

This zakat contribution is traditionally one of the five pillars of Islamic life. Moslems here, however, insist that it cannot be ordered by the government but must be given voluntarily.

"It's as if we all had cards that had to be checked to show that we prayed five times a day," said one resident of Lahore, passing through here while on pilgrimage to the holy city of Mecca.

Moreover, Zia's action angered Pakistan's minority Shiite sect, which comprises between 10 million to 15 million of Pakistan's 75 million people. They believe the tax should be voluntary and should be distributed in their own community, not lumped with everyone else's.

A Shiite protest in Pakistan's capital forced Zia to promise concessions to the Shiites, which are to be announced Sept. 15.

According to Western, Eastern European and Asian diplomats as well as Pakistani sources, Zia's martial law regime came within a hair's breath of losing power over that confrontation.

"If it had spread from Islamabad to Lahore and Karachi and there had been blood on the streets because of clashes between Shiites and Sunnidominated authorities, we would have a new general running the country," said one diplomat.

"Zia narrowly averted it. You've got to give him credit for that, but he provoked an unneeded crisis."

The Shiite protest reportedly was egged on by Iran, which has a large Shiite majority, thereby increasing tensions between the two neighboring countries. Both nations are in the midst of setting up Islamic governments.

As an indication of these tensions, Iran's religious and political leader, Ayatollah Ruhollah Khomeini, last month said that the Pakistan government along with governments of other nations such as Iraq, Egypt and Soviet-occupied Afghanistan are "deserving to be beheaded."

Perhaps more threatening to Zia's rule, however, are the jokes being told openly in the bazaars of Pakistan about the zakat tax.

Some people call it "Zia tax" instead of zakat . In Rawalpindi the other day, a group of men joked over how little money was given to beggars during the recent fasting month of Ramadan even though helping the poor during the holy period is considered an Islamic duty. They called Zia "the biggest beggar of them all" for taking all the money for charity.

"He grabbed the cash and ran," said Salmaan Taseer of Lahore, a member of the banned opposition party of executed former prime minister Zulfiqar Ali Bhutto. Taseer specifically asked that his name be used in reporting on opposition to Zia's program.

As a result of the sudden government expropriation of part of every savings account -- which netted $90 million -- Pakistanis are withdrawing money from the banks and investing in land, real estate, gold, gems and carpets, sources here said.

Trying to implement zakat symbolizes the problems the Zia government has had during the past 18 months in implementing Islamic law into a country that maintains a strong Western-style legal and education system that was formed during the British rule.

Three common crimes -- theft, robbery and adultery -- were brought under Islamic law in February 1979. The penalty for theft is loss of the right hand, the penalty for robbery is removing both the right hand and the left foot, and the penalty for adultery -- which requires so many witnesses as to be practically impossible to prove -- is stoning.

In the past 18 months, no limbs have been severed and no one has been stoned. The severest penalties imposed under Islamic law have been lashings, but none of those have been publicized in 11 months.

Reportedly three thieves were sentenced to lose their hands, but the government was never able to carry out the punishment since no doctor, including Army surgeons, would agree to perform the amputation.

Yet even matters seemingly as precise as cutting off hands can cause friction between the different Islamic sects. The Shiites complained that their interpretation of Islamic law calls for cutting off fingers to the first knuckle. This still permits the criminal to dip his right hand into the communal food bowl.

The majority Sunnis, though, want to cut off the hand at the wrist, which effectively bars a person taking meals with other people since using the left hand for eating is culturally offensive.

Zia, in a speech last month, called Western education and values the principal obstacle to the further Islamization of Pakistan.

He apparently aims to change that by removing Western influences from the education system. By adding Arabic as a required course, for example, observers here believe Zia will force the study of English to decline.

Similarly, the government is setting up separate universities for men and women. Textbooks are being reviewed for their Islamic content and Zia told a meeting of Islamic scholars late last month that several new ones are being written.

Some observers, however, see Zia building up a measure of personal popular support that he has not enjoyed since he overthrew Bhutto in a coup two years ago.

To administer the zakat fund, for instance, he established a network of local committees throughout the country. In Sind Province alone, there are 7,644 separate committees, each with seven members who will be distributing funds to the needy.

This could, in effect, turn into a Tammany Hall-type operation, with both the members of the committees and the recipients grateful to Zia.

Nonetheless, his program of Islamiztion remains unpopular with at least one segment of the society -- the better-educated, more articulate, largely Western-oriented stratum -- which continually derides it.

Even among that segment, Islam remains a dominant religious force. The question, though, is whether it will rule the total life of all Pakistanis, as Zia would like, or whether it will merely be the religion of the country.

"If we wanted a mullah to run the country we could have hired one for $50 a month," said one man in Lahore.