Why jesus christ was crusified?
The evangelical Lutheran view of Jesus Christ and the crucifixion is explained in a short article on the Church of Finland web site: http://evl.fi/EVLen.nsf/Documents/E32B80EF6B6E6392C2257325004114C5?OpenD...
A Google search will probably return more than enough articles and web sites that range from informative to imaginative ones.
You may want to start with the Wikipedia article on Jesus of Nazareth: http://en.wikipedia.org/wiki/Jesus. It also explains other views of Jesus and the crucifixion than the mainstream Christian teaching.