How does the apostle Paul attack worldly wisdom, and what Christian symbol does he connect his argument to?

Paul loved the symbol of the cross, but encouraged
followers to view it metaphorically; in other words, do not seek concrete evidence, or
as he termed it "worldly wisdom" when looking for the cross in everyday life. 
Christians must follow on faith, or risk missing what Jesus is trying to show us in our
everyday lives.  By focusing on "worldly wisdom", one is missing the spiritual aspect of
our relationship with God; God is present if we are open to receive him and his
blessings, but when we begin searching overtly for signs and signals, we only make it
more difficult for ourselves to experience His love and spirit.  Paul is trying to
explain to us that seeking the cross means we are seeking to live the way God wanted us
to live; the cross is a symbol to remind us that the ultimate sacrifice that was made
2000 years ago, the one that saved us all, and all we are asked to do is go forth and
live the way Jesus taught us.