Lawyers for Mobil Oil Corp. president William P. Tavoulareas and The Washington Post yesterday gave a federal court jury sharply divergent views about the accuracy of two 1979 articles that the oil executive claims libeled him and his son Peter.

In closing arguments, the opposing attorneys called on Biblical references to buttress their cases, cited the fine points of 16 days of testimony and implored the jurors to accept their respective versions of the 1974 creation of the younger Tavoulareas' London-based shipping management firm.

John J. Walsh, arguing his clients' $50-million libel claim against the newspaper, told the three-man, three-woman jury that The Post's articles about the Tavoulareases' business transactions were a "textbook example of irresponsible journalism" and urged the jury to award the damages "to show the world that it's time William and Peter Tavoulareas got a fair break."

Irving Younger, representing the newspaper, two of its editors, a reporter and a special correspondent, countered that the articles were "the truth of a complicated business transaction . . . the truth that William Tavoulareas does not want anyone to know."

The jurors will start to sort the conflicting claims this morning, after U.S. District Judge Oliver Gasch reads a lengthy list of legal instructions to them. The jurors will have different standards by which to judge the claims of each of the Tavoulareases.

In either instance, if the jury finds that the stories were true, the newspaper is not liable for damages. If the jurors believe the stories untrue and defamatory, in the case of the elder Tavoulareas they must determine whether the newspaper published them with the knowledge they were false or with reckless disregard for the truth. That is the standard of liability for a newspaper's statements about a public figure. Judge Gasch ruled that the Mobil president is a public figure.

However, Gasch ruled that the younger Tavoulareas is a private figure, and therefore the jurors, if they believe the stories untrue and defamatory, in order to award damages would have to find only that the newspaper was negligent in its preparation of the articles.

The case centers on Post articles that were published on Nov. 30 and Dec. 1, 1979.

The first article detailed how the elder Tavoulareas "set up" his son Peter in the London firm, Atlas Maritime Co., which in turn managed shipping operations for the Saudi Maritime Co. (Samarco), in which Mobil was a partner. The second article quoted allegations about the Mobil-Samarco-Atlas transactions, allegations made by Rep. John D. Dingell (D-Mich.) in a letter he sent to the Securities and Exchange Commission.

As more than 100 spectators watched in Gasch's packed courtroom, Walsh reminded the jury of one of the Ten Commandments, "Thou shalt not bear false witness," and said that there was "lots of false witness against William and Peter Tavoulareas" in the two stories.

Walsh charged that Post reporter Patrick Tyler, who wrote both of the disputed articles, and "the people at The Post weren't satisfied" with Mobil's rules that forbade the elder Tavoulareas from making any decisions regarding his son's firm.

"So they conjured up their own rules as to what a conflict of interest was," Walsh contended.

He cited a number of assertions in the articles, such as one that the Mobil president personally urged that George Comnas, Atlas' initial managing director, accept the younger Tavoulareas as a partner. Then Walsh looked at the jury and said, "The only problem with that: It's not true."

Comnas was Tyler's principal source for the Nov. 30 article, but he was not called as a witness. Walsh three times asked the jury, "Where was George Comnas in this trial?"

Younger told the jurors that more than 1,000 pages of deposition testimony had been taken from Comnas before the trial and that the Tavoulareases' lawyers could have read some of that into the record. Walsh had the last word on the issue, however, telling the jury in his rebuttal that Comnas was named on The Post's pretrial witness list, not the Tavoulareases'.

The newspaper's attorney, pacing the floor and gesturing frequently, recounted a number of instances in which the elder Tavoulareas dealt with Atlas matters and told the jury that "for all intents and purposes, he was negotiating for Atlas. And why was he negotiating for Atlas? He was taking care of his kid."

Leaning over the jury box railing, Younger emphatically declared that the elder Tavoulareas' dealings with Atlas were not conducted at "arm's length. It's father-son. Why? Because his son is with Atlas."

Younger noted the Mobil chief had been reading the Bible periodically at his courtroom table and said one passage he might note was John 8:32--"For ye shall know the truth and the truth shall make you free."

The attorney contended that the Mobil president believes that "anyone he disagrees with is wrong or a liar" and told the jury the articles "present everyone's side" of the Tavoulareas transactions.

The jury will also be considering a $20-million libel suit against Dr. Philip Piro, a Baltimore eye surgeon who was formerly married to the Mobil president's daughter, Patrice, and was Tyler's first source for the Nov. 30 story.

Piro's attorney, David Machanic, urged the jury to reject the claim, saying that Piro was "a responsible source. He did not lie."