Q&A: Is there a biblical warning about preaching about "good works" but ignoring Salvation?
You're basically describing the social gospel. I grew up in a social gospel church, and by that I mean a church that preached a message of social tolerance and loving they neighbor while ignoring the urgency of Jesus and His death on the cross. In fact, such churches actually define the word "Gospel" as doing good to their fellow man, through acts of kindness and benevolence. In other words, giving out blankets and feeding the poor is doing the work of the Gospel. I can never once recall hearing our pastor give an invitation for people to receive Christ as Savior.
The social gospel has been around for a very long time and whether or not there is a resurgence of that kind of preaching I can't say for certain. What I do know is that the age group that we refer to as Millennials (age 18-34) place a huge emphasis on social good works. It could be that what you're hearing is a renewed message tailored to reach that age group.
That being said, I don't know of a specific passage in the Bible that warns or condemns the preaching of good works while leaving out the cross of Christ. The New Testament writers assumed that the Gospel was all about Jesus and what He accomplished for us on Calvary. It would have been unthinkable for them to consider a message that ignored the death, burial and resurrection of Jesus.
That being said, the New Testament writers would also consider it unthinkable to separate good works from those to whom the Gospel had come. When the Apostle Paul spoke of a time when he went to Jerusalem to share and confirm his Gospel with the other Apostles, he described their meeting this way:
James, Peter and John, those reputed to be pillars, gave me and Barnabas the right hand of fellowship when they recognized the grace given to me. They agreed that we should go to the Gentiles, and they to the Jews. All they asked was that we should continue to remember the poor, the very thing I was eager to do. Galatians 2:9-10 (NIV)
Did you catch that? Peter, John and James had nothing to add to Paul's Gospel message, but what they did do was exhort Paul to "remember the poor" — something Paul said he was already eager to do. So it's clear that the early church practiced a balance of preaching Christ crucified for the forgiveness of sins, while at the same time exhorting believers to live a life of good works toward others — not for salvation, but because of salvation.