Missional Church, Culture and the Gospel

Just had an email from a good friends Jim, about the difference between Missional thinking/action and missionary (as in the modern missions movement).. He has come up with some great differences but one that I was uncomfortable with was that he stated Missional tends to separate, "Culture from Gospel, allowing people from other cultures to uniquely embrace Christ in the context of their culture without having to reject their culture or people."
I have been thinking of this for a while and concluded that I think the opposite is actually true, missional thinking and practice tends to allow culture to help us interpret and understand the gospel, without I might add slipping into Liberalism.
It is not that culture comes over and has more authority than the scripture but differing cultural understanding allow us to further and deepen our comprehension of the gospel.
Not then separate it more but actually draw the linking together.
take this quote from John Mbiti as an example on how a Christian undertanding of relationship can be further under stand through the eyes of another culture;
"In African under standing, the person is first identified in relationships. To be a person, male or female, is to have the gift of life and to belong in relationships. The primary relationship is an interpersonal kinship bond in which one could say: "I am because we are, and since we are, therefore I am."