As the 97th Congress of the United States ignominiously sinks into history, its members can be thankful for at least one thing: Christmas came along in time, and just barely, to save them from themselves. They obviously were incapable of doing so on their own.

It was a measure of the mess they were creating that even their chaplains, with the best of charitable intent, felt constrained to pray for them in special ways. Last weekend, for instance, when the Senate convened for what it hoped would mark the conclusion of a frustrating, wearying political year, its chaplain, the Rev. Richard C. Halverson, rose to pray:

Father in Heaven, as the confusion, tension and frustration of the past two weeks come to a close, we pray that our families will have priority in our interests and schedules. Help the senators and all who labor here to unwind gracefully, that these next two weeks will provide relaxation, rest and renewal.

The good minister was wrong. That wasn't the end, but only the beginning of another installment in what seemed an endless, embittering session.

Howard H. Baker Jr., the Senate's majority leader, wearily said he appreciated the chaplain's hope they would be able to unwind gracefully. But as for himself, he was finding it increasingly difficult to sleep. He faced each Senate session more grumpily than gracefully.

Later last Saturday Baker had more reasons for feeling grumpy. He was forced to make an unhappy announcement, he told his colleagues. The Senate was not going to be able to complete its business that Saturday after all. Senators would have to return at 6 the next night for what Baker called "the extraordinary request for a Sunday session."

But even that wasn't the end. The hours dragged on through the night and into the succeeding days, and nights again, and still the Congress droned along, its members growing nastier with each passing tick of the clock.

By Monday, even the Senate's chaplain was finding it hard to be charitable, spirit of Christmas notwithstanding.

He began his opening prayer by combining his message about the birth of Christ with a barely concealed sharp needle jabbed at the assembled senators: "Thou didst announce this cosmic event, not to the Roman senate, but to a handful of shepherds in the field."

And then he went on to intone:

Gracious Father, there is nothing about this powerful Senate, collectively or individually, which Thou dost not know. Our secret thoughts, desires, aspirations and ambitions are known to Thee. Thou knowest the compounding frustration felt by senators and their families as Christmas draws near and they are unable to be involved in arrangements that demand the attention of mothers and fathers. Practical, down-to-earth Heavenly Father, manifest Thy power and grace in this place today. Help the senators to finish the 97th Congress in an honorable way that will please Thee and bless the people. Fill this place with Thy love and peace. Dissolve any lingering enmity between members as the Senate comes to adjournment. We pray in the name of Him whose sacrificial love includes the least as well as the greatest. Amen.

Alas, there was little love exhibited in that chamber. The ugliest scenes were yet to come. When it was finally over, Congress, if not dishonoring itself, had lived up to the description given it by one of its members: this was no lame-duck, but a lame-brain session, said Paul E. Tsongas, a Democrat from Massachusetts.

It was Tsongas, too, who expressed perhaps the best lesson to come out of this miserable fiasco inflicted by such a handful of the shameful few at the expense of the many.

"I hope, at some time, that the leadership will recognize the need for a change of the rules," he said, on the Senate floor. "I want to put you on notice that, just as one member, I have had enough and I am going to engage in the same tactics. I am going to bring in all of the amendments I have cared for, lo these many years, and give you a chance to think about them. I may do it next year; I may do it tonight.

"But, at some point, like any other society, if the extremes run wild, the moderates have no choice but to pick one side or the other. And this is one moderate who is becoming very immoderate . . . . I wish to say, as far as I am concerned, that, absent some restructuring of the rules , that I intend, in the next two years that I will be here, to use the same tactics to further my own interests and hopefully force, if the moderates in this body go along . . . , change. Because it is obvious that the approach here is to accommodate, and to appease never works with fanatics. It is time to move in the other direction."

To which one of his fellow Democrats, Thomas F. Eagleton of Missouri, replied: "I think this 'trial by ordeal' that we have gone through for the past three or four days ought to be proof enough that our Senate rules are inadequate for the 20th century. They may have been adequate for the 18th or 19th, but they are certainly inadequate for the 1980s and the future.

"If this incredible experience that has been inflicted on ourselves as individuals, and on the country collectively, is to have any lasting beneficial meaning, then these rules which permit a handful to literally tie this Senate up in knots have to be changed. I can think of no other procedural priority for the new Congress than to accomplish the much-needed modernization of our now grossly out-of-date rules."

Amen, brothers and sisters. And let the rest you now enjoy cause you to reflect on the changes that must be made in the next, God help us, session of the United States Congress.