Imagine a teenager asking his mom for fifty dollars for a rare, collector's edition, LeBron James toilet seat cover. What would the response be? Now imagine a teenager asking her dad for fifty dollars to buy a study guide to help prepare for a college entrance exam. Assuming the first guy's mom isn't a collector of rare toilet seat covers, which request will get granted?
The request for the study guide would obviously be granted as it reflects a decision in line with the parents' plan for the girl's life.
In 1 John, we see John painting a picture of a similar attitude when it comes to our prayer life.
"This is the confidence we have in approaching God: that if we ask anything according to his will, he hears us. And if we know that he hears us—whatever we ask—we know that we have what we asked of him."--1 John 5:14-15
If we're where we should be in our relationship with God, close to Him spiritually and in tune to His direction for our life, our desires line up with His will for us.
Confidence in our prayer life comes from a close spiritual walk with our Heavenly Father. And what we want lines up with what He wants.
If you need more confidence in your life's direction, maybe you need to start by spending more time with God in prayer. Seek out God in prayer. Listen for His direction. And obediently following Him when you hear His call.