Whether we admit it or not, every single one of us has a bias. Do you have a belief? You have a bias. Do you have sympathy for a worldview? You have a bias. Are you vaguely aware of the meaning of any word in any language? You. Have. A bias. Everyone is biased. If you claim to be unbiased, you're heavily biased towards your own ego.
Bias, in and of itself, is not a bad thing. Imagine if we, as a society, thought it was. There'd be no such thing as a legal defence! "Your honour, I contend that my client is innocent, and will prove it with the following evid..." "YOU'RE BIASED! I declare your client guilty, and sentence him to the maximum punishment." It just wouldn't work.
And of course, you can be biased towards the truth. Just because a thing is true doesn't mean you're not biased towards it. If you know it is true, you're actually strongly biased towards it. And if you're right, that is a very good thing. So obviously bias, in and of itself, isn't a problem. Why, then, do people go to such lengths to pretend to be unbiased?
Obviously, bias can become a problem. An honest, natural, human bias can change. They do frequently. You have different biases today than you did as a child. But what if you just aren't willing to let a bad bias go? What if you're so unbelievably biased that if your bias is wrong, you don't want to be right? This is what people typically think of when they hear the word "bias". And that is when bias becomes a problem.
As a Christian, I have no problem listening to the "other side". I am extremely confident in my beliefs, and so in my own time, I am able to visit atheist apologetics websites, Youtube channels, I'll even read their books if I can obtain them for a cheap enough price. If it's not behind a pay wall, I'm quite comfortable listening to their arguments. I don't consider the source, I consider the arguments.
But other people, like the person in the screenshot in the header image, are obviously not so comfortable. This individual was provided a link to an apologist called Josh McDowell. I'm not familiar with McDowell (though I've heard good things, as well as bad things from atheists, which might as well be a good thing), but if an atheist is confident in their atheism, they shouldn't be afraid of him.
Now, in the interest of transparency, I usually do not visit links people give me either. I may do so in my own time, but in live debate, my policy is "my debate is with you, not the internet". When we play link wars, neither of us is really forced to think. We just Google the answers to each others' articles and share them, often without even reading them. But this is obviously not what this person was thinking. Note their reply. Rather than saying "my debate is with you, not the internet", it was to flat out admit that there are only so many sources they will accept. Why? Well, because they're "the least biased" and "most credible".
Translated, this means this individual is not only biased, but has also surrendered their ability to think. Substance is irrelevant. Content is irrelevant. If it comes from the "wrong source", it won't even be considered. If it comes from the "right" source, it will be accepted with minimal questions. Can you imagine if the exact same statement came from a Christian, listing a bunch of Christian sources as the "least biased" and "most credible"? Put it this way: Very often, this is the attitude of Christians. As a result, we all get accused of heavy bias. Not just the Christians who genuinely won't study other sources, but all Christians take on the reputation of the least reputable. Because, you know, the world is just biased against the Church that way.
To be sure, source does matter. Any idiot can make an argument. But dismissing them because of any personal attribute, including credibility, is called an "ad hominem", a well known fallacy that is frustratingly common to make. Whether someone is biased, or considered not credible, is irrelevant to the strength of their arguments. Truth does not change based on the one telling it. So, study the arguments, ignore the people presenting it, then see if it's worth accepting.
As a Christian, I am biased. I am biased towards the Way, the Truth and the Life, and I have no shame in admitting that. The shame is found in trying to pretend to be unbiased, as if you are the ultimate arbiter of truth. In truth, even God, who literally has infinite knowledge, is biased. And unlike for a human, it is entirely rational, even completely Holy, for Him to refuse to change those biases. Why? Because He already knows all. He can't learn anything. The foolishness of God is greater than the wisdom of men! (1 Corinthians 1:25). And for us, that can be both a blessing and a curse.
See, God has two very important biases. The first is towards righteousness. God simply cannot tolerate sin, and thus sin must be paid for. The second is towards us. He is not biased to the point of injustice, but to the point that though we deserve punishment, He is not willing to deliver us to eternal wrath. The solution? Pay for sin Himself. He sent Jesus to live as the only sinless human who ever lived. Yet, He died a sinner's death. He became sin for us so that we may become the righteousness of God in Him. Now, though we are all biased towards sin, we can turn from that (called "repentance"), confess Jesus as Lord, and believe He rose from the dead. In doing so, we can be raised with Him into eternal life. That is a bias worth having.