Does Salt Change With The Times?

My church - and I know it is not alone, as I read a lot about similar efforts online - is attempting to get our congregation into a new mindset for Evangelism by attempting to teach us about "Post-Modernism." Over the last couple of years, they have significantly changed the presentation, programs, and teaching of our church in an attempt to reach out to "a post-modern world." This has been a struggle for me. Not because I do not understand post-modernism. I am a philosophy major and a member of Generation X, so I have lived for years in a post-modern world with post-modern peers. What bothers me is the obvious attitude that the Church needs to be in a constant state of flux and change. The attitude seems to be the Church needs to change to meet the shape of the World, no matter what shape the World takes on.

I am stuck between two verses. One is the one that the "changeable Church" proponents would turn to.

To the weak I became weak, to win the weak. I have become all things to all men so that by all possible means I might save some.
1 Corinthians 9:22

This verse seems to be spot-on in indicating that the Church should change in any way required to win some to Christ. The other vserse is one that seems to stand against a "changeable Church."

"You are the salt of the earth. But if the salt loses its saltiness, how can it be made salty again? It is no longer good for anything, except to be thrown out and trampled by men.
Mattthew 5:13

This verse seems to indicate that the Church needs to be timeless. It needs to maintain its distinctives, and must watch to ensure that it does nothing to lose its ability to be a preservative in the world. It implies that the Church needs to avoid being changed by the World.

Which is supposed to be our model? Or it it supposed to be a mixture of the two? It is always dangerous to hang a whole philosophy on a single verse. It is always safer to grab the message from the whole of scripture. But here I can not see which is the right way. What are the thoughts of Mod-Bloggers out there? Where is the proper balance?