What I've learned through Christ in all of my experiences, are when it's OK to expose vulnerabilities and when it is not. I'd like to share a bit of my experience with you for you to consider.
I've always loved vulnerability. Mostly, in part, because if someone exposed their vulnerability, it made me feel less dysfunctional in all my past experiences, poor choices and life lessons I've learned along the way. It's always nice to see someone "successful" say... "I didn't always have a life like this..." because it does a couple things in my head. 1) Provides hope and 2) puts me on the same level playing field as a successful person. Well that is all great...but is that what matters in the kingdom? Perhaps slightly...but not fully.
So that thought on the back burner for now, simmering on low, let's get on to another side dish... When do I recommend it's OK to be vulnerable? Well, my "old answer" would be, it's only OK to be vulnerable with people that you know have a heart for you, that you trust, that are fully dependent on Christ, who will be there for you, walking it out with you. Until...the church wounded that perspective for me. Let me explain... Several years ago, I was medically diagnosed with Rheumatoid Arthritis, which is an autoimmune disease. A few years back, they found nodules on my lungs and in my lymph nodes. It's not hard for you to guess where my thoughts might have gone during that time. Also during that time, I was in conflict in a relationship with one of my brothers/sisters in Christ. So when I went to ask the church for prayers, I got a "you got this", "make sure to pray", "before you send an email to people about your issues, give it to God" and "I can't be there because there is a sale going on at Menards, but I'm with you in Spirit." Understandably, I was crushed. In my head I was fighting the most crucial battle of life in my head, yet it was a pepper flake in the ocean of our church. Now, whether that was my perspective, or truth, regardless, I was crushed. I left the church for 2 years, and learned how to be fully dependent on Christ. My point is not to put blame on anyone, but to simply show how our dependence on people can be very tainted and a very weakness in our walk with Christ.
Which brings me to my best answer...
When you are dependent on Christ you should be vulnerable in all you do, at all times, with all people.
2 Corinthians 12:9-11 New King James Version (NKJV)
And He said to me, “My grace is sufficient for you, for My strength is made perfect in weakness.” Therefore most gladly I will rather boast in my infirmities, that the power of Christ may rest upon me. Therefore I take pleasure in infirmities, in reproaches, in needs, in persecutions, in distresses, for Christ’s sake. For when I am weak, then I am strong.
2 Corinthians 12:9-11 International Standard Version (ISV)
but he has told me, “My grace is all you need, because my power is perfected in weakness.” Therefore, I will most happily boast about my weaknesses, so that the Messiah’s power may rest on me. That is why I take such pleasure in weaknesses, insults, hardships, persecutions, and difficulties for the Messiah’s[b] sake, for when I am weak, then I am strong.
2 Corinthians 12:9-11 The Message (MSG)
Because of the extravagance of those revelations, and so I wouldn’t get a big head, I was given the gift of a handicap to keep me in constant touch with my limitations. Satan’s angel did his best to get me down; what he in fact did was push me to my knees. No danger then of walking around high and mighty! At first I didn’t think of it as a gift, and begged God to remove it. Three times I did that, and then he told me,
My grace is enough; it’s all you need.
My strength comes into its own in your weakness.
Once I heard that, I was glad to let it happen. I quit focusing on the handicap and began appreciating the gift. It was a case of Christ’s strength moving in on my weakness. Now I take limitations in stride, and with good cheer, these limitations that cut me down to size—abuse, accidents, opposition, bad breaks. I just let Christ take over! And so the weaker I get, the stronger I become.
It's scary to be vulnerable. Whether you are in a secure and safe environment or an environment filled with people that want nothing more than to take your weakness and exploit it. Regardless of it being in a church or the world. But the truth is, that in order to receive God's healing, peace, joy, or any other Godly attributes over that vulnerability you need to get it out into the light. The light meaning out of the darkness. If it's kept in secret, it's stewing in the darkness and you are only allowing Satan to have access to it. You have to be willing to release that vulnerability and give God permission to touch it, giving God full access to it. Putting your full trust in God and His love for you, His plans for you, and His purpose for life in abundance! Regardless of who you confess this vulnerability to, people can not fix it... only God can. You are not releasing this darkness on human shoulders, you are simply releasing it so God can heal it... And God will do above all you can do or think with this vulnerability for the good of the kingdom, regardless of what people might do with it.
Be vulnerable...let God be God and work in every inch of your life!