Let me ask you a question: Do you do this with other areas of your children's lives? Do you, for example, let them make up their own minds whether or not it's a good idea for them to go out and play in a busy street, or swallow pills from your medicine cabinet, or play with some open cans of paint? I seriously doubt it.
Why, then, should you neglect the most important relationship they can ever have which is their relationship with God? God created them, and He put them here for a purpose. More than that, He loves them, and He wants them to love Him in return. He loves them so much that He wants them to spend eternity with Him in heaven. Can you think of anything more important? This is why Jesus rebuked His disciples when some of them tried to keep children away from Him: "Let the little children come to me, and do not hinder them, for the kingdom of God belongs to such as these" (Mark 10:14). These words are for you as well.
I can't help but wonder, however, if the real issue here is your own attitude toward God. Is He important to you or is He only an occasional thought? Don't neglect your own soul, but turn to Christ and open your heart to Him. Then ask Him to help you teach your children about His love and the plan He has for their lives.