I was raised a Missouri-Synod Lutheran. In undergrad I took a Sociology of Religions class and wrote my term paper on the differences between MS and ELCA. As others have noted, ELCA definitely tends to be more socially liberal. I can not imagine returning to a MS Lutheran Church.
From
http://experts.about.com/q/956/3795472.htm
The difference between Lutheran churches is major! I will attempt to point out some of the major areas:
Evangelical Lutheran Church in American: teaches salvation outside of Chrisitanity, favors women pastors, leans towards homosexual rights and ordination, teaches evolution, and is fairly pro-abortion.
Wisconsin Evangelical Lutheran Synod: Scripture alone is rule, therefore, in Christ's words, Christ is the only way to salvation; does not favor women pastors (or voters),
opposes gay rights and views homosexuality as a sin, teaches creation, and
is strongly pro-life.
Lutheran Church Missouri Synod: Scripture alone is rule, therefore, in Christ's words, Christ is the only way to salvation;
does not favor women pastors but allows women to vote in the church, opposes gay rights and views homosexuality as a sin, teaches creation, and is strongly pro-life.