What are the three main ideas in chapter 1 of Freire's Pedagogy of the Oppressed?

In his book Pedagogy of the Oppressed, Paulo Freire advocates a revolutionary program for education and liberation among the oppressed people of the world. In chapter 1, Freire explains the dualistic paradigm which holds that the world is comprised of the oppressors and the oppressed. According to Freire, those who are oppressed are dehumanized by their oppressors. As a result, the oppressed seek freedom and justice, even if they do not realize it or know how to achieve it.
Based on the view of the world that divides people into the categories of oppressor or oppressed, Freire suggests a new approach to education that would address these problems. He calls this approach the pedagogy of the oppressed. According to this perspective, the oppressed can overcome their oppression through an educational process in which they are active participants. The pedagogy of the oppressed requires oppressed people to recognize and adjust their roles in their own oppression. Freire writes,

The pedagogy of the oppressed is an instrument for [the oppressed’s] critical discovery that both they and their oppressors are manifestations of dehumanization.

Finally, a third point in chapter 1 of Pedagogy of the Oppressed is that liberation of the oppressed is both necessary and difficult. Freire explains that, for liberation to occur, the oppressed need to play an active role in becoming conscious of their situation and voluntarily working to change it through self-empowerment. Liberation cannot be forced onto the oppressed by revolutionaries or activists. Without genuine participation in the process of their liberation, the oppressed will never be truly free.
To summarize, the three main ideas of chapter 1 are the following:

The world is made up of oppressors and the oppressed
A “pedagogy of the oppressed” is necessary—not only for education, but also for freedom and justice
Liberation is a mutual process in which the oppressed must actively participate

Freire first begins by noting that a main problem with transforming the world into a better place in which people can become fully human is that oppressed people internalize the mindset of the oppressor and identify with it. As Freire puts it,

It is not to become free that they [the oppressed] want agrarian reform, but in order to acquire land and thus become landowners—or, more precisely, bosses over other workers.

Freire also writes,

The oppressed, having internalized the image of the oppressor and adopted his guidelines, are fearful of freedom.

Secondly, the oppressors themselves are dehumanized by the system in which they function. They try to soften both the oppression they inflict and their own dehumanization through acts of "generosity." However, this "generosity" perpetuates a system of oppression: if people were treated as fully human from the start, they wouldn't need charity or handouts. Therefore, the fight for freedom liberates both the oppressed and the oppressor. It is an act of love:

And this fight, because of the purpose given it by the oppressed, will actually constitute an act of love opposing the lovelessness which lies at the heart of the oppressors violence, lovelessness even when clothed in false generosity.

Third, those fighting oppression must reeducate themselves (the system of oppression can't provide this education) to value not becoming the "new bosses" in a new system that simply replicates the old. There is an exit from the world of oppressor and oppressed: it is transformation. Transformation means that the conditions that create oppression must be changed. This transformation comes in part from education—reading and learning—but also, and this is extremely important to Freire, through action (which he calls "praxis"). People can't just dream about a new world, but must work to make it happen. He quotes the psychologist Erich Fromm that humans need the

. . . freedom to create and to construct, to wonder and to venture. Such freedom requires that the individual be active and responsible.

People, oppressed and privileged, must realize they are dehumanized by the current system and fight that oppression through transforming the world. The world is transformed through education and action into a new way of being.

Freire's three major points in chapter 1 begin with the concept of humanization and dehumanization. Humanity is what makes humans who they are. Freedom is an example of an aspect of humanization that contributes to how people grow as human beings. On the other hand, dehumanization is where an individual's humanity has been taken away. Dehumanized individuals are considered oppressed. Oppressed individuals are oppressed by other people. The oppressors control others by taking away their rights. This process causes the oppressors to also become dehumanized.
Secondly, Freire states that the oppressed are in danger of becoming the oppressors. This is due to the fact that they are living within the structure the oppressors have created for them. Freire discusses how the oppressed often become comfortable within the system of the oppressors. Acting against these structures puts the oppressed in opposition to the oppressors and creates turbulence. The oppressed can overcome these structures, but they must work together.
Lastly, Freire goes on to encourage oppressed groups to rise up together and break free of the structures placed upon them by their oppressors. The oppressed must create their own pedagogy of liberation rather than have it created for them. They must investigate (as a group) what elements of oppression exist within the structures of society and create a pedagogy of liberation for all.