Saul Mkhize may turn out to be not only a martyr in the peaceful campaign against racial discrimination in South Africa - but a cause of healing progress in that campaign. The latter outcome depends on whether all sides follow through on the possibilities of positive response in the aftermath of Mr. Mkhize's shooting by police earlier this month. He was killed in a crowd of fellow black villagers who had made him their leader in trying to resist government removal from farmlands owned by them. The scheduled removal would add 5,000 or more to some half million black people already forced into resettlement camps after decades of residence in ''black spots'' surrounded by white South Africans.
What conceivable good could emerge from the tragedy of Mr. Mkhize?
In the first place there was the example of his own unsung persistence in peaceful means of protest. Shortly before he was slain he had written a courteous letter beseeching help from Prime Minister Botha. He said the villagers did not want to be ''rebellious in any way'' but only to continue to live their lives in their own environment.
Was there a hint of answering humanity in the government position? The minister of law and order expectedly defended the police but added the less usual comment that the death was ''regrettable.''
The US State Department likewise departed from recent custom, uttering a strong public criticism of South Africa's arbitrary relocation of people on an ethnic basis. The US has offered some criticism of South Africa since President Reagan took office, notably when South Africa conducted cross-the-border raids in Lesotho. But under his policy of ''constructive engagement'' the stress has been on quiet diplomacy. In response to Mr. Mkhize's shooting, the State Department made no bones about asking for a full investigation and reiterating its longstanding disapproval of South Africa's divisive policy of segregating the black population in ''homelands.''
Another positive thread in the aftermath of tragedy was the South African regime's decision not to crack down on protesters gathered at Mr. Mkhize's funeral on the weekend. The police could have acted under a law prohibiting political speeches and songs at funerals.
As it was, the village burial site was inundated with anti-apartheid protesters virtually canonizing Mr. Mkhize. By then white South Africans far and wide knew about the formerly obscure village leader, and perhaps a few more of them were added to the ranks of the nation's white questioners of apartheid.
Yet another strand to be noted was the determination of villagers not to let political outcry totally rule a day they preferred to solemnize with mourning and prayer. Agreement was reached to permit both approaches to continue.
Here was a valuable reminder. For all the necessary political activity in the world's country-by-country achievement of freedom, there is a fundamental hope and strength in the prayer that sets men free.