Following are excerpts from the prepared text of President Carter's address to Congress :

Mr. President, Mr. Speaker, members of Congress of the United States, fellow citizens:

The truth of the nuclear age is that the United States and the Soviet Union must live in peace - or we may not live at all.

From the beginning of history the fortunes of men and nations were made and unmade in unending cycles of war and peace. Combat was the measure of human courage. Willingness to risk war was the mark of statecraft.

My fellow Americans, that pattern of war must now be broken forever.

Between nations armed with thousands of thermonuclear weapons - each capable of causing unimaginable destruction - there can be no more cycles of war and peace. There can only be peace.

About two hours ago, I returned from three days of intensive talks with President Leonid Brezhnev of the Soviet Union . . .

The talks in Vienna were important in themselves.But their truest significance was as part of a process - a process that began long before I became President.

This was the tenth time since the end of World War II that American and Soviet leaders have met at a summit. During these past three days, we have moved closer to the goal of stability and security in Soviet-American relations.

That has been the purpose of American policy ever since the rivalry between the United States and the Soviet Union became a central fact of international relations a generation ago, in the wake of World War II.

With the support the Congress and our people, every President throughout this period has sought to reduce the most dangerous elements of the Soviet-American competition.

When the United States still had a nuclear monopoly, President Truman sought to place the atomic bomb under international authority. President Eisenhower made the first proposals to control nuclear testing. President Kennedy negotiated the Atmospheric Nuclear Test Ban Treaty. President Johnson broadened the area of negotiation to include strategic arms. President Nixon concluded the historic firstStrategic Arms Limitation Treaty. President Ford negotiated the Vladivostok accords. This is a vital and continuing process.

This week I will deliver to the Senate of the United States the complete and signed text of the second Strategic Arms Limitation Agreement - SALT II.

This treaty is the product of seven years of tough, painstaking negotiation under three Presidents. When ratified, it will be a truly national achievement - an achievement of the Executive and the Congress, of civilians and the military, of liberals and conservatives alike, of Demorcrats and Republicans.

SALT II will not end the competition between the United States and the Soviet Union.

That competition is based on fundamentalyy different visions of human society and human destiny. As long as that basic difference persists, there will always be some degree of tension in the relationship between us. The United States has no fear of such rivalry. But we want it to be peaceful.

In any age, such a rivalry risks degenerating into war, but our age is unique, for the terrible power of nuclear weapons has created an incentive for avoiding war that transcends even very deep differences of politics and philosophy. In the age of the hydrogen bomb, there is no longer any meaningful distinction between global war and global suicide.

Our shared understanding of these realities has given the world an interval of peace - a strange peace, marked by tension and danger and sometimes even regional conflict, but a kind of peace nonetheless. In the 27 years before Hiroshima, the leading powers of the world were twice engulfed in total war. In the 34 years since Hiroshima, humanity has by no means been free of armed conflict, but there has been no world war.

Yet this twilight peace carries the ever-present possibility of a catastrophic nuclear war, a war that in horror and destruction and dealth would dwarf all the combined wars of man's long and bloody history.

We must prevent such a war.

To keep the peace, we must have strong military forces, strong alliances and a strong national resolve - so strong that no potential adversary could be tempted to attack us. We have that strength - and the strength of the United States is growing, not diminishing.

Yet for the same reason - to keep the peace - we must prevent an uncontrolled and pointless nuclear arms race that would damage the security of all countries, inculding our own, by exposing the world to a greater risk of war through instability, tension and uncertainty.

That is why the new Strategic Arms Limitaion Treaty is so important . . .

This treaty will withstand the most severe scrutiny, because it is so clearly in the interest of American security and world peace. . . .

The SALT II Treaty reduces the danger of nuclear war. For the first time,it places equal ceilings on the strategic arsenals of both sides, ending a previous numerical imbalance in favor of the Soviet Union.SALT II preserves our options to build the forces we need to maintain the strategic balance. The treaty enhances our ability to monitor Soviet actions. And it leads directly to the next step in controlling nuclear weapons.

SALT II does not end the arms competitions. It does make that competition safer and more predictable, with clear rules and verifiable limits where otherwise there would be no rules, no limits.

It is our interest because it slow - even reverses - the momentum of the Soviet arms buildup.

Under the treaty, the Soviet Union will be held to a third fewer strategic missile launchers and bombers by 1985 than they would have - simply by continuing to build at their persent rate.

With SALT II, the number of warheads on missiles, their throw weight, and the qualitative development of new missiles will be limited. The Soviet Union will have to destroy or dismantle some 250 strategic launcher systems - systems such as nuclear submarines armed with relatively new missiles and aircraft carrying their largest multi-megaton bombs. Once dismantled, these systems cannot be replaced. By contrast, no operational U.S forces will have to be reduced. For one Soviet missile alone - the SS-18 - the SALT II limits will mean that some six thousand fewer Soviet nuclear warheads can be built and aimed at our country.

With or without SALT II we must modernize and strengthen our strategic forces - and we are doing so. But SALT II makes this task easier, surer and less expensive.

The agreement constrains none of the reasonable programs we have planned to improve our defenses. Moreover, it helps us respond much more effectively to our most pressing strategic problem - the prospective vulnerability in the 1980s of our land-based missiles. The MX missile permitted under SALT II and its verifiable mobile deployment system will enhance stability as it deprives an attacker of the confidence that a successful furst strike could be launched against ICBMSs. Withoot the SALT II limits, the Soviet Union could build so many warheads that any land-based system, fixed or mobile, could be jeopardized.

With SALT II, we can concentrate more effort on preserving the bounds in our conventional and NATO forces. Without the SALT treaty, we would be forced to spend extra billions each year in a dangerous nuclear arms race.

As I have said many times, SALT II is not based on trust. Compliance will be assured by our own nation's means of verification, including extremely sophisticated satellites, powerful electronic systems and a vast intelligence network. Were the Soviet Union to take the enormous risk of trying to violate the treaty in any way that might affect the strategic balance, there is no doubt that we would discover it in time to respond fully and effectively.

It is the SALT II agreement itself which forbids concealment measures, interference with our monitoring and the encryption or encoding of crucial missile-test information. A violation of this part of the agreement - which we would quickly detect - would be as serious as a violation of the limit on strategic weapons themselves.

Consider these prospects: Suppose the Soviet leaders build 1,000 additional missiles, several of advanced and formidable design. This can happen only if the SALT II Treaty is defeated.

Suppose the Soviet leaders double the number of warheads on their existing missiles, triple the annual production of the backfire bomber and greatly increase its range and payload. These things can happen only if the SALT II Treaty is defeated.

Suppose the Soviet leaders encrypt all data on their missile tests, to conceal their nuclear launcher deployment rate and hide all existing missile launchers. This can happen only if the SALT II Treaty is defeated.

SALT II is very important it is more than a single arms control agreement. It is part of a long historical process of gradually reducing the danger of nuclear war - a process that we must not undermine.

The SALT II Treaty must be judged on its own merits - and on its own merits is a substantial gain for national security and international stability. But it would be the height of irresponsibility to ignore the possible consequences of a failure to ratify the treaty.

These consequences would include:

Greatly increased spending for strategic arms;

Greater uncertainty about the strategic balance;

Vastly increased dangers of nuclear proliferations among other nations throughout the world; and

Increased political tensions between East and West, with a greater likelihood that other inevitable problems could escalate into superpower confronatations.

Rejection would also be a damaging blow to the Western alliance. All of our European and other allies, including especially those most directly and courageously facing Soviet power, strongly support SALT II. If the Senate were to reject the treaty, America's leadership of the alliance would be compromised, and the alliance itself would be severely shaken.

In short, SALT II is not a favor we are doing for the Soviet Union. It is a deliberate, calculated move we are making as a matter of self-interest - a move that happens to serve the goals both of security and of survival, that strengthens both the military position of the Untied States and the cause of world peace. . . .

Militarily, our power is second to none. I am determined that it will remain so. We will continue to have the military power to deter agression, maintain security, and permit the continuing search for peace and the control of arms.

Economically, despite serious problems of energy and inflation, we are by far the most productive nation on earth. With our allies, our economic strength is three times greater than that of the Soviet Union and its allies.

Diplomatically, we have strengthened our friendship with Western Europe and Japan, China and India, Israel and Egypt, and much of the Third World. Our alliances are stronger because they are based not on force but on common interests and most of ten on common values.

Politically, our democratic system is an enormous advantage - not only to each of us as individuals, but to all of us togetheras a nation . . .

These strengths are such that we need fear no other country. This confidence in our nation helped me in Vienna as we discussed specific areas of potential direct or indirect confrontation around the world, including Southern Africa and the Middle East.

For instance, I made it clear to President Brezhnev that Cuban Military activities in Africa, sponsored or supported by the Soviet Union, and the growing Cuban involvement in the problems of Central America and the Caribbean, can only have a negative impact on U.S.-Soviet relations.

Despite disagreements our exchange was useful because it enabled us to clarify our positions directly to each other, face to face, and thus to reduce the chances of future miscalculations on both sides.

Finally, President Brezhnev and I developed a better sense of each other as leaders and as men. The responsibility for many decisions involving the future of the world rests on me as the leader of this great country, and it is vital that my judgments be based on as much firsthand knowledge and experience as possible. In these conversations, I was careful to leave no doubt about either my desire for peace of my determination to defend the interests of the United States. I believe that together we laid a foundation on which we can build a more stable relationship between our two countries. . . . CAPTION:

Picture, Saying that Americans and Soviets "must live in peace - or we may not live at all," Carter appeals for SALT II support as Vice President Mondale listens. By Joe Heiberger - The Washington Post