I disagree with your analogy in comparing witnessing with a surgeon’s skill.
If you have the attidue that you won’t share your faith until you have it perfect then you have a very small view of what God can achieve with you.
If I adopted your attitude to everything in my life then my church would not have its current children’s ministry coordinator.
Even people coming out of Bible College into ministry will find that they don’t “know it all” in relation to being the pastor of their church. You can’t improve on what you have until you use it, make mistakes and learn from them.
So if I share my faith in a less than perfect way - well at least the person I’ve shared with can’t front up to heaven on judgement day and say “well nobody told me that Jesus died for me!”
At some point that person will have to respond and investigate it further. They shouldn’t just take my word for it but go and read their Bible. That’s where the gospel is! Not in a tract.
If I get the message a little bit wrong - at least I know where to send this new convert so they can hear the correct gospel - in their local church setting and with other Christians in bible study.
But first I have to get them there.
In the fellowship of believers, kind regards,
Heather. :-)