Isn't it strange how so many people have that type of story, yet we spend a lot of effort imposing those lessons we learn on others. The first problem in most cases is that no two people have had the same journey. So, although a lesson may make complete sense to one person, it makes absolutely no sense to another. The second problem is that there is no guarantee the "lessons" you think you have learned are actually faulty conclusions. It's actually amazing to watch how the perspective of a preacher's sermons change based on time, experience, and life's struggles. This is because we continually process information and change our perspectives to make sense of the world around us. It's sort of like programming a computer - you can only expect out of it what you put into it.
In John 16, Jesus states that the Holy Spirit will lead us to truth. But, what does that mean? Does He just tell us the truth? In my experience, people don't want to hear the truth. In fact, we tend to fight the truth when it conflicts with our "programming". The truth seems illogical, ridiculous, and impossible. So many times, I hear people say that the Holy Spirit told them something that I believe is just so contradictory to the Word, God's character, and even logic itself. But, they continue on that track because their interpretation of something that is supposedly "of the Spirit" is nothing more than attributing to Him what you want Him to say.
So, who is reliable? The answer is pretty obvious - no human being. Everyone has flawed programming. Everyone has their own perspective and understanding. Everyone, believe it or not, has their own theology. Does it match God's? Probably not 100%. So, how do we convince people of truth that we are not certain about.
The answer is in letting the Holy Spirit lead. Show your fruit. Use your gifts. Demonstrate your genuine love. Be yourself. Then, watch God work. Allow Him to speak by Himself instead of feeling like you have to preach mini sermonettes in order for people to "get" God.
Understand that it is rare that an individual believes that something is theirs if their did not earn or find it themselves. Your personally valuable conclusions are cheap to everyone else. They take the form of words that are meaningless without the experience that inspired them. I encourage you to start experimenting with simply living as the person you know God wants you to be and allow yourself to be open to the ideas around you. Share your views as perspectives, not conclusions with a period at the end. You will find that the Holy Spirit is a competent teacher, and He will use your journey to bless and enhance others along the way. At the end, the person who finds their way will glorify Him and only Him and your treasures are secured in the safest of savings accounts.