It's true that our nation has been deeply influenced by Christianity; many of our original settlers came here so they could practice their faith freely, and many of our laws reflect our Judeo-Christian heritage.
But unlike some countries, people in America are free to practice any religion, or no religion at all. Most people today would still claim to be Christians, but in reality many of them (like your fellow workers) don't take it seriously. Unfortunately, when God or the Bible aren't taken seriously, this leads inevitably to moral chaos, as we see all around us today.
I sense that in your heart you wonder if God is real, and I want to assure you that He is! More than that, God loves you and wants you to come to know Him as your friend. The proof is that slightly over 2,000 years ago He came down from heaven in the person of Jesus Christ.
Do you want to know what God is like? Ask your local bookstore for a modern version of the Bible, and begin reading about Jesus in the section called the New Testament. (I recommend starting with the Gospel of John.) In addition, you can find information on our website to help you (billygraham.org). Jesus' promise is for you: "Ask and it will be given to you; seek and you will find; knock and the door will be opened to you" (Matthew 7:7).