How are Mr. Obi and the villagers similar?

It is important to note that the author, Chinua Achebe, produced a body of work largely concerned with the cultural impact of British influence in Africa through colonization. In the case of “Dead Men’s Path,” there is a cultural division happening, but it is not black against white—it is two sets of Africans that are in conflict with each other. Mr. Obi and his wife represent those native Africans who have had the “excellent” education that the British schools provide—an education which focuses on eradicating pagan or heathen beliefs native to the land in order to bring Africa into the modern age. Mr. Obi himself says it best when describing his own school:

“The whole purpose of our school… is to eradicate just such beliefs as that… our duty is to teach your children to laugh at such ideas.”

Obi himself laughs at the village priest and attempts to eradicate the footpath.
Both groups are countrymen, both are passionate about their beliefs and opinions, and at the end of it, both are heavily focused on building a world that produces a better Africa. The village priests argue that the best thing for the population is to maintain tradition, while Obi argues that it is best to eliminate it. Ultimately, they both want what is best for the community, though they disagree with what is the best way to achieve this.

Michael Obi and the villagers of Ndume are both tenacious people who will not turn from their course.
In Mr. Obi's case, he's convinced that creating a school that changes the values of the community is the right thing to do. He doesn't consider what the community wants. Instead, he blazes ahead with his own plan even when he's advised to find a way to blend the two cultures. He has no interest in doing so. He's absolutely confident in his methods and approach.
In the same way, the villagers are tenacious about getting their access to the path restored. After he refuses to let them use the path and a woman dies giving birth, they are convinced that is why. Mr. Obi's belief that spirits aren't an issue and have no effect on their lives doesn't resonate with them. Instead, they're tenacious about getting him removed and access to the path restored.
Neither Mr. Obi nor the villagers are willing to compromise.

Michael Obi is a young, zealous headmaster and a staunch proponent of modernity. Michael Obi wishes to turn the Ndume Central School into a modern, progressive institution by educating the villagers and vehemently rejecting their traditional ways of life. When Michael Obi notices a woman walking on the traditional village footpath leading through the school's compound to the village shrine and cemetery, he ends up blocking the path. After the village priest urges Obi to open the footpath because of its significance to the village's culture and religion, Obi refuses to compromise and the villagers end up destroying the school's hedges and gardens. While Michael Obi and the villagers have drastically different perspectives on modernity and tradition, they are both zealous and passionate. Obi's determination to block the ceremonial path is matched by the villagers' insistence on keeping it open and accessible. Both Michael Obi and the villagers are willing to go to great lengths to succeed in regards to blocking or opening the ceremonial footpath.