Do we add an unspoken set of rules to our evangelism? Do we place additional expectations on Christians, maybe not overtly but certainly implied, that we have a particular culture that we expect them to conform to? I think that we do and I am sure I have contributed to this. To make it more confusing there are a myriad of very different church cultures from local church to local church and also by geographic region and ethnic background. In essence what we are preaching is not "Christ and Him crucified", it is "Christ and Him crucified and our church culture".
When we go to the world and preach Christ, we do so in the expectation that (whatever your soteriology) some people will respond. Those people will not be out of the box American Christians (and we probably don't want them to be!). They might be former drug users or alcoholics. They might come from broken homes. We need to give people the grace and the room to grow in Christ and support them in that process, not expect that they will conform to us in every respect before they become "one of us". Every Christian is one of us the moment they are born-again. That is not my rule, that is His.
Even people who have been Christians for a long time are going to be at different stages of their maturation in the faith. It is not like we have any consensus on...well on much of anything, but boy do we try to make people conform to us. Please note there is a difference between taking a stand and erecting a wall. I can take a stand that I think wives should cover their heads and even argue in favor of that practice without saying that I will only fellowship with families where wives cover their heads. Being willing to extend grace to others and welcome them as the family members that they in fact already are is not compromising my principled positions, it is recognizing that adoption and unity in Christ is of paramount importance.
We also need the humility to recognize that we probably don't have everything figured out quite as much as we think we do. I only need to look at my blog over the years to see that as I submit and study scripture, I find myself modifying positions. I hope that I am doing so in a way that moves away from external cultural piety and into a more authentic walk as a follower of Christ rather than just waffling.
I am not saying that doctrine and practice are unimportant. I just don't think that it is my calling or my right to dictate to people the terms under which I will accept them. In fact I am pretty sure that one of the most preeminent doctrines, a first tier, non-negotiable doctrine, is that God has ordained the conditions for accepting us and that we are obligated to freely accept those that He has already accepted.