Well, I can harp on and on about the topsy-turvey climate we're living in. So what can Christians do? In taking on the task of being a light in this darkening world (Phil. 2:15), we must be spiritually equipped before anything else.
Prayer obviously is the first step--and I mean a focused prayer. It must be noted, as one famous preacher recently noted, that Jesus never taught his disciples to preach, but to pray.
Now, when I talk about focused prayer, it may not necessarily be super-specific.
Jesus, for example, told his followers to pray for the promise of the Father, the baptism in the Holy Spirit, and further told them they would be witnesses to the entire world as a result (Acts 1:4, 5, 8). But there were no specifics beyond that—they did not know that they would be supernaturally empowered by the Spirit, that 3,000 people would be saved after Peter's prophetic message, that a massive community of believers would spring up in Jerusalem, that the gospel would progress from Jerusalem to Rome itself ...they prayed simply what Jesus told them to pray.
Churches can and should follow this. For example, instead of having the usual Bible study at my church this week, I had a short teaching at what we need to pray for, then spent the rest of the time in prayer at the altar (I learned this basic pattern at the church in Florida where I was an associate pastor). It was a powerfully anointed time of prayer! We all prayed for specific people who were unsaved or backslidden; for laborers to be raised up for the harvest (Matthew 9:35-37), and for a fresh vision from God for being a light in the community and the world.
So far as being spiritually equipped through prayer, fasting and almsgiving (the latter two will be discussed soon), George Grant gives an excellent discussion of this in his book from the 80s, Grand Illusions: The Legacy of Planned Parenthood. He discusses these exercises in the context of fighting the evil of abortion, but these principles should be a normal part of the Christian's life.
We can endlessly expose President Obama's destructive agenda, decry the numbness of America's conscience, and spotlight the pseudo-Christian groups like Matthew 25 Network, who bandy about Jesus' Name while contradicting the Bible. But as Grant puts it in his book, you can't fight something with nothing. Only by remaining true devotion to Jesus, and shining His light in this dark world around us, can we advance God's kingdom (see Matthew 6:1-13).