Scriptures from the world's major religions say the gods have voices like rushing waters. That description may be difficult to understand until after a visit to the massive Iguacu Falls in the lush jungle bordering Argentina and Brazil.

Visitors don't hear the roar of the falls with their ears as much as they feel its power reverberating through their bodies.The power of the falls can be sensed miles away, even before the cataracts themselves are heard by the ears or seen with the eyes.

Visitors traveling to the falls may feel vibrations from the falls before they can - by standing still - begin to separate the distant low grumbling of the water crashing onto rocks from the noise of nearby cars and talking.

Soon, the spray and perpetual rainbows that rise hundreds of feet above the falls and tropical rain forest become visible.

As visitors walk closer to the falls, their roar builds in a crescendo until people standing at the brink of the most powerful cataracts are unable to hear each other even when yelling.

But the falls are never painfully loud. Instead of wincing from the high decibel level, most visitors seem not to notice it. Instead, they are carried away in reverie by the spray, the beauty and the feeling of power rumbling through every fiber of the body.

The falls are unsurpassed for beauty. Iguacu is ranked by travel writers along with Niagara Falls and Victoria Falls in Africa as the world's three most spectacular.

Iguacu (pronounced "e gwah soo") means "great waters" in Guarani, an aboriginal language of the region. That appropriate name was given to the Iguacu River, which is more than two miles wide before it seemingly falls sideways over the Parana plateau into a narrow canyon 237 feet below.

The resulting falls are among the widest in the world, extending more than 2 1/2-miles. That makes them four times wider than Niagara Falls and 50-feet higher. That is one reason Igaucu Falls have been described as "an ocean falling into an abyss."

Iguacu is not just one big waterfall. It is more than 275 separate, side-by-side cataracts separated by tiny and large islands in the river. The falls range from garden-hose sized trickles to the massive "Garganta del Diablo" (the Devil's Throat), named for the powerful grumbling sound it makes.

The bottom of Devil's Throat is never visible because of the great amount of spray thrown up by the water crashing onto lava rocks. The updraft from the rising mist may also ruffle visitors on the Argentine side who can stand almost directly over the falls because of catwalks leading to it.

The border of Argentina and Brazil also passes directly through the middle of Devil's Throat. The falls occur only 14 miles east of where the Igaucu flows into the Parana River, a boundary point shared by Brazil, Argentina and Paraguay.

The falls at Iguacu are arranged not exactly in a horsehoe, but in more of a check-mark shaped figure with one side long and one side short. The falls are broken up at points by islands in the river.

Good panoramic views of the long rows of falls are available on both the Argentine and Brazilian sides, and airplane and helicopter rides are available that offer the most spectacular vistas.

However, the thick jungle plant growth hides some of the falls from view unless visitors stand almost on top of them.

In 1965 Argentina constructed a system of wood and concrete catwalks around, over and beneath the falls. One trail follows the top of the falls to the brink of Devil's Throat. Each curve offers a different and more exhilarating view than the last. It also gives visitors the chance to lean over the top of some of the cataracts, and watch the water fall and crash far below.

Another trail goes down the side of the canyon through the jungle to the base and side of the falls, including some cataracts that would otherwise remain hidden.

The trails allow visitors to experience close-up the jungle, which adds greatly to the beauty of the falls.

Numerous species of colorful parrots and butterflies are common, and an occasional toucan with its long, colorful bill may also be spotted. Everything is green, except for the ground and water, which are a brownish red - the same shade as the Colorado River and surrounding sandstone in southern Utah.

The red water creates interesting effects with some of the falls. The color makes them look more like thin carmel syrup than water.

Both Argentina and Brazil have formed national parks around the falls, which has helped preserve their natural beauty by preventing an intrusion of too many hotels and shops.

High class hotels are available, however, on both sides of the falls - but they are expensive. The rooms usually have large balconies with excellent views of the falls. Less expensive accommodations are available in the nearby towns of Foz do Iguacu on the Brazilian side and Puerto Iguazu on the Argentine side.

Puerto Iguazu has several shops featuring famous Argentine goods such as sheepskin coats, wool sweaters and leather goods. A ferry between Puerto Iguazu and Foz do Iguacu is also available. Dorado (golden salmon) from the river are featured in the restaurants and make a tasty meal.

A worthwhile side trip, even though it is more than 100 miles away, is to the spectacular ruins of San Ignacio Mini, a Jesuit mission built in the 1600s, burned in 1817 and not re-discovered in the Argentine jungle until 1897.

But the hotels, side trips and shopping take a back seat to experiencing the majestic power of the falls. Visitors will definitely hear the sound of the Devil's Throat, and will even get a good sampling of what hearing God's "voice like rushing waters" may be like.

The visit is guaranteed to be overwhelming, and humbling.

* For information on travel to Brazil call the Brazilian Office of Tourism, at (212) 286-9600, or write it at 551 Fifth Avenue, Suite 519, New York, N.Y. 10017.