Faith is not something that "happens" or "we make happen". Faith is rather the beginning of a long journey that starts with a willingness to entertain the possibility that there is Someone in charge and it is not us. We engage various ways to examine the possibility that the God of Abraham, Isaac and Jacob as manifest in the Christ has something worth exploring. We might read about the Christian faith, or dive right into reading the Bible. We might also include or be lead to prayer and a conversation with the Creator of the Universe. At some point the information and experience overcomes our need to be in control and we say, "OK, God. Show me how to do this thing called faith. Let it change how I view the world and let it inform the way I serve the world."
Or, we fumble around feeling something is missing, or start embracing addictive behaviors to try to "feel something" or "not feel something" and at some point it dawns on us that the thing we thought we could control is controlling us and we start a conversation with "God, if you are there and it is OK for me to talk to you..."
Or, we are raised in a family of church-goin', Bible readin' folks and at some point we realize faith is more than coffee and conversation and whether this pastor is "good" as the last one. We notice that some of the folks seem to be getting more out of their relationship with God than we are and we start to ask questions, try new things like a Bible study or participate in a service opportunity and then we realize that we can have a much more important life if we are willing to change.
In other words, faith comes in a lot of different ways. In the church folks are often asked to "share their story" or "share their testimony" and this means they are invited to tell of some important event or the chronological story of how their journey of faith has made a difference in their life. Some are amazing (the beloved pastor who served 7 years in a federal penitentiary 20 years ago; or the person who nearly died as a result of self-will-run-riot living, but is now a contributing member of their community; or the woman who decided to be a missionary when she was 7 years old and went on to bring body and soul healing to a remote village half way around the world. Others may be less spectacular, but more comforting because they are folks who seem so like us, not someone whose name is known outside of a small circle, but whose love and kindness shines light into some very dark places.
I think that most important element of faith is the willingness to keep seeking, to know more, understand better, love more courageously, to live more authentically because the more we grow in faith, the more we find God to be all that we hoped and more: love, light, truth, consistent, trustworthy, powerful. The “proof” is in the living as we consistently experience God to be and do what God says God is and will do.
There are folks who believe if a person has not had a "fire and rushing wind" experience on a specific noted date that they are not part of God's family. But I find no scripture to support this, a "litmus test Christianity". Instead, I believe we are responsible to start where we are and keep opening more fully to God with God’s own help. If it includes an experience that I felt for myself was an in-pouring of the Holy Spirit, that is fine. If it starts as part of an intellectual journey, that is fair too. Sometimes in includes back-sliding (see especially the Old Testament folks like Moses, Abraham, Isaac, Jacob and David and St. Paul in the New Testment to learn more).
But God never gives up on us. So if you find you have been distracted or even willfully uncooperative, stand up, or get off your high horse and dust off your derriere; offer a humble heart to the God who never gives up on you and you will find God never really left you at all.