I read people who argue against Christianity. I want to hear their case in their own words, including the parts that are difficult to answer. Reading a Christian author's response can help, but I want to know what the person being answered actually said.
Otherwise, it is easy to mistake familiarity with a rebuttal for understanding an objection. I might know the answer a friendly author gave without knowing whether it addresses what the skeptic meant. I would rather discover that while reading than halfway through a conversation with someone whose question I thought I understood.
This kind of reading has strengthened my faith. When I compare the explanations, I continue to find the Christian account persuasive. The alternatives often ask me to accept assumptions I find less convincing than the beliefs they are meant to replace. But I know which conclusion I favor going in. I have to watch the temptation to accept a weak argument from my own side while demanding much more from the other. Reading the original author gives me a better chance of noticing when I have been too quick to dismiss something.
Some of that discipline came from graduate school. Years ago I started a Master of Arts in Christian Apologetics at Liberty University. I am still enrolled, but the coursework is on hold. I got married, two more children arrived, and the degree had to wait. The classes I completed required me to work with serious objections, explain them fairly, and then respond. A paper answering an easy version of someone else's position would not do. I did not finish the degree, but I kept that habit.
I also take 1 Peter 3:15 seriously. Peter tells believers to be "always being prepared to make a defense to anyone who asks you for a reason for the hope that is in you" (ESV). I read that as a responsibility to understand and explain what I believe. Reading skeptics is one way I prepare. If an objection keeps coming up, I want to know enough about it to give a considered answer.
Peter also specifies gentleness and respect. Those are owed to the person asking, whether I find the argument impressive or not. Still, reading someone carefully helps me remember that there is a person behind the objection, with reasons for finding it convincing. I can disagree firmly and take the trouble to understand those reasons.
That matters when the discussion moves from a book to a conversation. The person in front of me may have a different concern from the author I read, even if the opening question sounds familiar. I need to hear them out. If I have misunderstood, I need to let them correct me before I carry on answering.