RICHARD PRYOR is officially back, and to those who were worried that his highly publicized cocaine freebasing accident and subsequent finding of God would tone down his act will be reassured by the opening line of Live on the Sunset Strip: "I'd like to talk about something serious tonight: fucking."

Obscenity is an integral part of Pryor's routines. The greater portion of his vocabulary is comprised of George Carlia's infamous "Seven Dirty Words You Can't Say on Television." If either of Pryor's movies ever ran on television, it would last about ten minutes--five of which would be credits.

Vulgarity has helped to make Pryor one of America's foremost stand-up comedians. His constant barrage of obscenities is so over-whelming that it eventually has a numbing effect; after a while, one ceases to notice the four-letter words and obscene gestures.

Pryor's jokes, however, go somewhat deeper than the language he uses to tell them. During Live on the Sunset Strip, Pryor takes the opportunity to talk about sex, drugs and the condition of Blacks in America. And, he lends credibility to his jokes by drawing them from his personal experience.

He speaks, for instance, of his visit to the Arizona State Prison, which, he discovered, is 80 percent Black. "But there are no Black people in Arizona," he notes. Surprised to find that all the prisoners really belonged behind bars. Pryor said he had always thought "Black people only killed other people by accident."

Pryor speaks also about the decline in sexual activity that accompanied President Reagan's arrival at the White House, about discovering masturbation at the age of ten--which he rather graphically simulates--and about picking up Playboy bunnies. It is standard Pryor material: offbeat, offensive and riotously funny. It does not scale the heights of his first movie. Richard Pryor in Concert, but it doesn't miss by much. Live on the Sunset Strip is the sort of movie one would want Jerry Falwell. Anita Bryant and perhaps Nancy Reagan to be chained to the front row of the theater and forced to watch with eyes propped open Clockwork Orange style. It's that rude.

The trouble is, every once in a while Pryor gets the urge to be humanitarian, to show that beneath his vulgar exterior lies a man aware of the seriousness of the subjects he is discussing. Much in the same manner that Don Rickles takes time out from his usual barrage of insults to remind us that we should all love each other regardless of race colour or creed. Pryor interrupts his routine a couple of times to say things like "Racism's an ugly thing. I hope someday they give it up." "This is all well and good, but it is very out of place in his act and somehow out of character. After all, it's coming from a men who has just been talking about having to move to a Black neighborhood because "When you live around white people, anything can happen." Equally out of place is a story he tells of his trip to "The Motherland--Africa," where he noticed there was no "inferior" race, a realization which caused him to cry. It made him give up using the word "nigger," which he says is a "word we use to describe our own wretchedness."

PRYOR BECOMES MOST unclear during the most serious part of the movie. He devotes the last half hour of his act to his free basing accident and the details of his cocaine addiction. He tells the story, however, as he would any other routine, showing how the pipe he used to smoke the drug ruled his life and then how he rejected the help of concerned friends. Pryor mixes serious judgments ("If you have been free basing longer than two weeks, you are a junkie") with lighter observations ("Of all the people free basing, have you ever heard of anybody blowing up?"). It is, in the end, difficult to tell whether Pryor is speaking out against free basing or if he is just warning people to be more careful when they do it.

His comments about what it was like to catch fire are as funny as they are grotesque. Again, though, it is hard to know if Pryor's jokes are really going to turn people off to cocaine. Catching fire taught him an important lesson: "When you are on fire, running down the street, people will get out of your way." One burn, however, ran after him, asking. "Hey, buddy, can I get a light?" While Pryor was on the table in the emergency room, he claims he heard one of the orderlies say. "Why don't we get some cole slaw and serve this stuff up?" Pryor ends the routine by thanking God for not burning his private parts.

Now, there is no law that says Richard Pryor must speak out against cocaine, although it would seem somewhat destructive to have him advocating its use. If he is against it, his message is too subtle. If, however, we simply take Pryor at face value and don't worry about what he is trying to say, he is still one of the funniest comedians now working.