This term may very well refer to the gospel that the apostles preach, but it can also refer to Jesus Christ, for he is both “the Word” and “Life.” John most likely meant both the person of Jesus Christ and the message of life that he embodies in himself.1 This understanding also echoes the very words of Jesus in John 11:25 and John 14:6.
1 That which was from the beginning, which we have heard, which we have seen with our eyes, which we looked upon and have touched with our hands, concerning the word of life