Why only investing, if you want to succeed in anything you should stop relying on God for outcomes. Whether God exist or not, that's a controversial question but personally I started doing much better in all respect when I stopped praying for outcomes.
My mother spends 4 hrs in prayer and since childhood I was also a strong believer in God and thought whatever is happening to me is because what god or fate has decided for me until one morning in 2000 when I went up at 4 A.M in the morning, just before my IIT entrance exam, for a hawan (as suggested by my mother) to crack the exam. No wonder I couldn't secure even last rank in the prelim itself. Inside I knew I was not prepared and asked for support of god to help me pass the exam. I was blamed that without preparation even God doesen't help. I thought if I am fully prepared then why should I ask the support of God. It's like asking for wheel chair when your legs are absolutely fine.
When I started Investing in Stocks, my Mother started suggesting me the stones to wear, the days I should trade and above all the days I should not trade at all. I was even recommended stocks to buy based on my favorable stars. Though I occasionally followed her tip in the beginning out of self doubt but I was increasingly getting convinced that stocks in long terms move on fundamentals and in short term based on sentiments.