False religion can be traced all the way back to the first person born to woman: Cain. Had Cain not known what God expected of him, God would not have rejected his offering. Notice that God did not reject Cain's offering because it was not the best he had to give, but because he brought what he wanted to bring, and not what God required (Gen. 4:1-7). That very well could be the definition of religion! It reminds me of an old Frank Sinatra song: "I Did it My Way!"
Today, there are millions of different religions. Some still worship the things God created rather than worshipping Him as Creator (Rom. 1:22-32). In Paul's day, there were even Greeks who worshipped "THE UNKNOWN GOD" (Acts 17:23), just in case. One source stated that "there are 330,000,000 Hindu gods" (All About Religion). Another source said, "Buddhism is a non-theistic religion, meaning that the nature of God is not pertinent to Buddhist teachings. In Buddhism, gods do exist, but are largely imported from early Vedic (Hindu) teachings" (Answers.com).
Christianity is no exception. The very fact that there are thousands of denominations, most of which claim to be the true form of Christianity, illustrates that it is simply just a man-made religion like all of the others. With the exception of one group which falls under the heading of Christianity, all teach a false Gospel which require religious works to be "saved."
The Gospel message states that Jesus Christ accomplished all that is necessary for a man to be "saved" from his sin, and to become a child of God. Jesus said, "It is finished" (Jn. 19:30). Paul stated that it is faith in the death, the burial, and the resurrection of Jesus the Lord, which "saves" us and makes us children of God (Rom. 8:14-16; 10:8-17; 1 Cor. 15:1-4; Gal. 3:26; Eph. 2:8-9). John's Gospel describes the spiritual transformation which takes place when one places his trust in Jesus as being "born again" (Jn. 3:3-8), and Peter said that a person is born again when he believes the Word of God (1 Pet. 1:23). Obviously, Peter was referring to the Gospel, which is the "power of God unto salvation" (Rom. 1:16).
There are millions of "roads," but only one leads to heaven (Jn. 14:6)!