I firmly believe that the main reason you're questioning your present attitude is because God is at work in your heart, trying to show you the futility of your disbelief and pointing you to a better way. I pray you won't try to silence His voice!
And why is God doing this to you? It isn't because He's just trying to win an argument with you and convince you that He is right and you are wrong. He is creating these feelings in you for one reason: He loves you and wants you to discover the joy and peace that come only from knowing Him. If He didn't care about you He wouldn't bother with you -- but He does care, and He is pursuing you and seeking to draw you to Himself. The Bible says, "I have loved you with an everlasting love; I have drawn you with loving-kindness" (Jeremiah 31:3).
How can you know not only that God exists, but also that He loves you? Look at Jesus Christ as He is found in the pages of the New Testament -- for He was God in human flesh. Not only that, He gave His life for you, and He rose again to give you eternal life.
The greatest truth any person can ever discover is that God loves them and has opened the way for them to be with Him in heaven forever. Don't let your pride, or anything else, keep you from turning to Christ and putting your faith and trust in Him.