The irony between society and religion
There is an implicit, systemic irony between religion and politics, because although the two spheres seem disconnected (the vast majority modern Westerners agree they should be separated), Spinoza notices that all the people in power are still people, which means they probably have a religion, which means they probably inherited religious beliefs from their parents and community. They are connected in the most crucial way—they are both properly within the domain of philosophy, and they are directly related because of religious morality.
The irony of religion as a bad thing
Spinoza says that the problem with religion is that mixed in with the hope and beauty of certain religious ideas, people have also added their brokenness and closed-minded assumptions into the tradition. He says religious people who want to impose their point of view against others, to enforce their view of the world as law—those people have been part of the church the entire time. He says that a scrutinizing look at Christianity would show the evidence of brokenness and judgmentalism, mixed in with encouraging ideas.
The irony of religious people
Spinoza might seem to hate the Bible, but actually he's just tired of the humans who talk to him about the Bible. That is highly ironic in multiple ways, including the irony that actually, the Bible's content is not really debated in this, but rather the way people act around the Bible. Spinoza's fight is not really with the authors of the Bible or its content, but actually, his fight is only with religious people who say he has to care what the Bible says in the first place.
The irony of time
When Spinoza talks about his modern day, that's 350 years in the past to the modern reader today, but that number will continue to grow. However, although in many ways, the earth seems timeless and eternal, it is changing, because as people like Spinoza say their piece, the rest of us get to think through those ideas in a quicker way than Spinoza's way, which was to live a long, difficult life with many enemies. Time is changing our culture as we are brave enough to say the right things that fix our societies.
The irony of order and rule
The irony of safety is that it comes at the cost of freedom, and in this case, the religious safety that is found by giving ascent to religious ideas you don't actually believe—that only leads to a slavery that is not even secure or comfortable, says Spinoza. The truth that Spinoza is willing to admit, but his religious family and friends will not admit, is that religion is about authority and social order, and it is an attempt to conform humans into an obedient person.
