However, my understanding is that -- if you want to measure cultural decline broadly, by looking at crime rates (especially murder rates) -- things are getting way way better. Historians of crime estimate that number of murders per 100,000 was vastly higher in the Middle Ages than it is today. (I'd be interested if anyone knew of a good paper on this).
Life has become more precious because families are smaller and so it is more traumatic when someone dies: First, an industrial economy encourages smaller, nuclear families. Second, the rise of a social safety net means that people don't have to have huge families to support them when they're too old to work.
To the extent that American families are being torn apart, etc. The problem isn't a lack of God, or spirituality, or too much materialism -- it's that average people need to work longer and harder and they don't see their families as often. When everyone worked a 40 hour week, there was plenty of time for civil society (bowling leagues, rotary club, coaching your kid's baseball team...). Those kinds of activities just seem quaint now.