If you want to grow spiritually, the place to start is with God.
Faith is confident trust in God and the salvation He provides in His Son Jesus Christ.
You will find what you are looking for when you realize God has placed those longings in your heart as a divine desire; your hunger is a gift from God to draw you to Him. It's a holy want with a holy fulfillment. Everything you really need and want is offered by and found in Him.
At present we are on the outside of the world, the wrong side of the door. We discern the freshness and purity of morning, but they do not make us fresh and pure. We cannot mingle with the splendours we see. But all the leaves of the New Testament are rustling with the rumour that it will not always be so. Some day, God willing, we shall get in.
Why don't people ask us about our hope? The answer is probably that we look as if we hope in the same things they do. Our lives don't look like they are on the Calvary road, stripped down for sacrificial love, serving others with the sweet assurance that we don't need to be rewarded in this life.
You cannot devote your life to an abstraction. Indeed, life shatters all abstractions in one way or another, including words such as "faith" or "belief". If God is not in the very fabric of existence for you, if you do not find Him (or miss Him!) in the details of your daily life, then religion is just one more way to commit spiritual suicide.
God doesn't expect us to be a walking encyclopedia of biblical knowledge. He wants us to know Him, to be in a relationship with Him. This means not only hearing but allowing our understanding of God to change the way we live. Like the wise builder who laid the foundation of his house on the rock, we learn to let our knowledge of God change us.