You know that's not true, right? Believers ALWAYS know what to do - ask God. I've committed to stop saying I don't know because, to repeat, it's not true, and because I'm as Yeshua is. He's connected to The Father and has access to everything Yahweh has and I'm seated right there with Him at the right hand. All I've gotta do is tap His arm and ask for wisdom and it's mine.
There are tons of verses that come to mind that guarantee I'll receive what I ask for. I'm not going to list very many because I'm too lazy to look up the addresses right now, but one of my faves is: If you ask anything according to God's will you can be sure He's heard you. And if you know He's heard you, you can be sure you'll receive whatever you've asked for because you asked according to His will. Bam!
You can win as much as you want to, Christians. It's your choice.