I'm scared.

[Crossfire]

I'll try state my thoughts as plainly as possible. Basically, I just had a major panic attack- for a minute, I started to doubt God's existence. I'll be honest and say I haven't been living a "Christian's life" lately, but I've never... well, thought about the possibility of Him not existing. Until 3 minutes ago, that is. I freaked out. I don't know what came over me.

Edit: Okay, I've calmed down a bit. Still have no clue as to what exactly happened.

[Cleanedbyblood]

I used to know a guy who had panic attacks a lot. He used to tell me that sometimes the best thing is to just let them pass. When you started doubting God's existence it could mean the devil had a grip on you (that happens to me at time & I just say out loud "Devil, I belong to Jesus, now leave me alone!" Then I take a moment, if I can and either say a small prayer or read the Bible)

[MrKrillz0r]

I'm somewhat used to having panic attacks when my OCD gets bad. I believe that the only cure is to read the Bible, pray and so on. Though you should try to avoid breathing fast, and instead try to think things through, while breathing deep and slow.

Praying! Don't give in to these lies, put for focus on Christ instead!

[SierraLea]

Check out the St. Michael Prayer. There's a lot of versions, so here's the one my family uses.
St. Michael the Archangel, defend us in battle.
Be our protection against the wickedness and snares of the Devil.
May God rebuke him, we humbly pray.
And do thou, o Prince of heavenly hosts,
By the power of God, thrust into Hell Satan and all evil spirits
Who prowl the world seeking the ruin of souls.

Also, check out Thomas Aquinas's Five Proofs. They should reassure you.

[Yuki-Anne]

I think having doubts is a natural part of your faith developing. I'll admit that sometimes I also have scary moments where I wonder if the God I've dedicated my life to does not exist after all. In these moments I think about 1 Cor. 15. And I also think about the many impossible things in my life that have happened.

In these moments, pray. Don't be afraid to just be honest with God about your fears and doubts, and ask Him to help you with them.

It also doesn't hurt to talk to people you know who are strong in their faith.

Also, I'll recommend reading "Letters to a Skeptic" and "The Case for Christ," which both present concrete evidence for the Christian faith, that you can come back to and remind yourself of in times of doubt.

[Atria35]

I'm siding with Yuki. I think that having doubts - whether it's of God himself or whatever Christian theology you have - is something necessary for growth. If you never doubted or explored other ways of thinking, then your spiritual state would be completely static, and that's not very spiritually healthy.

And that moment of doubt also means that you are better equipped to understand where aetheists and agnostics stand. That is something I think every Christian should understand. It means you are being led to explore your reasons for believing even more deeply. Christians who've never doubted can never truly understand where nonbelievers are coming from - that disbelief bridges the two sides.