The moral decay of today's culture is not something new; human nature is the same today as it was thousands of years ago. In the book of Amos, God showed the prophet a striking image of how far HIs people had moved away from Him. In the vision, the Lord used a plumb line to show how a wall was no longer upright. God said He was going to hold His people to a similar test to show how far they had drifted from His commands.
The drift away from God is usually a gradual thing. As a people, our culture begins to slip from the original standard. What once shocked us loses that power. What we once would not allow in our society finds its way into our everyday lives. If we aren't careful, we begin to see it as "normal." But just as God held the plumb line up against Israel, He will one day hold it up against us. We will see, in glaring reality, just how far we have drifted from upright. So, we go back to His standards and remind ourselves of how things should be. For us, we choose to live by His standards, not those of this world.