With the topic of religious truth being so popular these days, many people believe the best course of action is to say "well, we can never really know the truth, so why live as if one stance is objectively true?" This is, while technically philosophically different from atheism, practically speaking the same thing. Assuming we can't really know which religion or lack thereof is true, the default position is to act as if none of them are true. But is this a sensible solution to the often confusing conundrum of religious quandaries? Let's take a look at what it means, using a practical example.
Say you are a sergeant in the US army. Your squad is deep in enemy territory, and you've completed an important mission. At this point, you are attempting to get to a safe zone, but are being followed by many enemy soldiers. You are currently camped in the most defensible position you can find, but you know it won't hold out for long against the enemy. You need to know if there's a way out, so you send out 4 of your best men on reconnaissance, and you also order some other men to interrogate some local villagers. Your presence in this territory is not popular with the locals, so you're not sure if you can trust them. But at this point, you're looking for any option to survive.
Eventually, everyone you have sent out returns. And they all have good news! The men you sent out on reconnaissance all agree on one point: there is a gap in the enemy forces that can be easily exploited to escape. You will have to take your squad through as quickly as possible, though, because the enemy intends to close in soon.
The men you sent to interrogate the villagers also have good news, but theirs is different from what your spies brought back. Their reports also, for the most part, don't agree among themselves. Some of them say that there is another way out through the soldiers - this is a popular claim, but most of them are pointing in completely different directions. A few even say that the enemy is actually not there at all! They claim that they left some time ago - or maybe were never there to begin with.
Now, as the commanding officer, you are left with a choice. You are responsible for the lives of every man in your squad. You can listen to the testimony of your spies. They have been shown to be reliable in other matters, and you have no reason to doubt them now. Except, of course, that their testimony is different from the varying claims of the villagers. If you wish, you could trust the locals, even though their stories vastly differ among themselves. But why not just pick the one you like best? The claim that the enemy doesn't even exist is particularly attractive. After all, you haven't really seen any of the enemy yet personally - you've been focused on staying as far away as possible. Perhaps you can stroll back to base camp unharmed, without worrying about the possibility of being shot.
One thing is certain, though. The only decision that you can't make is to stay where you are. If there is an enemy, they will be attacking soon. And if there is not an enemy right now, then they will eventually find you. And your soldiers have homes and families to go back to. You need to make sure they survive. To do this, you can choose to trust any of the testimonies presented to you - but you absolutely cannot stay where you are. Sure, it's impossible to really know which option is true. But the choice of no choice is guaranteed to have consequences. You will stagnate in your camp until you die, one way or another. The choice of no choice is the choice of throwing your life away - and the lives of all of your men.
Agnosticism is choosing to take no action in the face of incredibly important consequences. Even if you choose to believe that there is no God, then you are at least being intellectually honest. The consequences will be exactly the same as if you chose no choice, but they will be the result of a real choice. And it's not even a particularly difficult choice! The testimony found in the gospels is presented by reliable eyewitnesses. Truth be told, they are some of the best historical documents available to us. (Seriously, click the link up there. If you get that book you will not regret it.)
In Revelation 3:15-16, God sent a message to the church in Laodicea. He said "I know your works, that you are neither cold nor hot. I could wish you were cold or hot. So then, because you are lukewarm, and neither cold nor hot, I will vomit you out of My mouth." That's agnosticism. Lukewarm water. It's not a "safe" middle ground - it's the choice to either condemn your squad, or make them wait for nothing.