If the resurrection life is simply an extension of THIS life, the potential for domestic strife is unlimited in the situation the Sadducees described to Jesus here. The Sadducees were so bound to their tradition that nothing Jesus said could really make any difference to them or change them in any way. But that doesn't mean Jesus didn't try. Jesus explained to them that conditions in the next life just cannot be compared with life in the here and now. It's an apples and oranges thing.
Tradition IS important.
Tradition is important. That has always been a problem in the church, from day one to this day. We don't seem to want to leave any room for revelation when we're talking about tradition. The church is called to be the agent of change in the world. The purpose of the church, then, is to change the world by changing people in the world, one at a time, not to preserve the status quo, to keep things the way they've always been, as the religious leaders of Jesus' day tried to do.