I've been asked that question a few times lately. Well, the answer is simple. I have experienced proof of His existence, that is how I know. Would you like to hear my proof?
In 2001 I discovered "personal relationship" for the first time with God. Before I always knew about God but then I was discovering that I could actually know God. In order to get to know him I felt like I should read the Bible for the first time, front to back. (Looking back now I can see that was the Holy Spirit moving me.) Anyhoo, as always God's timing is PERFECT. I was in Genesis about the time that Moses was in Egypt chatting up Pharaoh when I was in desperate need of a job. I had applied for a job at Publ!x where I had worked for 12 years previously when they told me that I may possibly be hired back into management instead of hourly. I had the hourly job if I wanted it or I could go for the management position. I went for management again as it would solve all my financial needs perfectly. The problem? Everything was going perfectly smoothly for me.....the District Mgr who was in need was my old store manager from my days in Florida and I was his back door vendor receiving/accounting girl. Ahhh, he loved me back then....surely this was going to be a piece of cake.
But, after great phone interviews with him he said he would call me back with an answer in a day or two. Guess what, two weeks later I still had no phone call. I was about a month from being in the worst of worst circumstances with money. I needed him to call immediately with an answer in the worst way.
I knew I was going to have to call him. It was the only way to find out for sure so I could take the hourly position if I had to. The big problem with this is when I get nervous I cannot speak worth a lick. I stammer, my voice quivers like you just can't imagine, folks...it gets ugly. Plus, I am not good at selling myself or pushing people (back then at least). I knew my phone call would not be a welcomed intrusion as he told me not to call him and that he would call me. I was scared to death and it was the very last thing I wanted to do. I was sitting in my bedroom reading my Bible and studying Moses talking to Pharaoh with his brother. Then it hit me.....
This is the proof part. Moses had a speech impediment and God called him to speak to Pharaoh. Moses begged God to let his brother come along with him to help him speak because this impediment was keeping him from being a good communicator. God gave Moses permission to do just that. This was my big moment with God. I got down on my knees and prayed. I told God that I was like Moses. I can't speak when I get nervous. I said "Lord, I will make this phone call if I have to but you know that I will mess it up and it won't go well and I will not end up getting hired. Lord, I'm asking you to have this man call me as I will be confident and not mess up if he calls me. I am asking you for an Aaron in the way of him calling me instead. I will wait until 12 noon and if he does not call by then I will make the phone call myself. I believe you hear me and will help me." And that was my prayer. I finished studying my Bible and anxiously waited for the phone to ring. It was the first time I ever read the Bible and put what I read into practice. I was stepping out of "religion" and into "relationship".
At 11:30 am I was still fully believing that God was going to show up like He did for Moses. I just believed, don't ask me why. I just did. Now remember this phone call is two weeks late in coming and I was in no way expecting him to call me for any reason that day except that he was two weeks late calling already. Well, at 11:45 the phone rings and it is the District Manager from Pub!ix. Do you know what he said to me? After apologizing for not calling me back he said he was going about his day and I just popped into his head and he realized he forgot to call me. He was going to call me later in the day and he said it was just nagging at him to call me so he finally did. He wasn't even in his office and said he'd have to call me back to schedule anything but he wanted to let me know I was hired.
Oh MY. Y'all I dropped right to my knees in holy reverence for the King of Kings and the Lord of Lords who just showed up and proved His existence beyond a shadow of a doubt for me right then and there. That nagging feeling to call me was God putting me in his mind. That was God answering my prayer and nobody can tell me otherwise. I said by noon and he called at 11:45, no way was that a coincidence.
Now to me, that's a pretty good proof God exists story. I like to look at this transition in scripture this way:
Jeremiah 29:11-13 (New International Version)
11 For I know the plans I have for you," declares the LORD, "plans to prosper you and not to harm you, plans to give you hope and a future. 12 Then you will call upon me and come and pray to me, and I will listen to you. 13 You will seek me and find me when you seek me with all your heart.