What does Revelation 22:14 mean?

The washing of robes as mentioned here is a metaphor for purification from uncleanliness, meaning sin. This verse pronounces a blessing on those who are cleansed from their sin—a reference to those who are saved through their faith in Christ (Ephesians 1:7). This is the seventh blessing given in Revelation. The previous six are in 1:3; 14:13; 16:15; 19:9; 20:6; and 22:7. The righteous are allowed into the eternal city, New Jerusalem, and have access to the tree of life.

By washing His disciples' feet, Jesus provided an object lesson about spiritual cleansing. Peter objected at first and then when Jesus told Him, "If I do not wash you, you have no share with me" (John 13:8), Peter requested Jesus to wash his hands and head as well. Jesus replied, "The one who has bathed does not need to wash, except for his feet, but is completely clean. And you are clean, but not every one of you" (John 13:10). In one sense, Jesus was referring to the difference between a ritual and a "real," full cleaning. He was also distinguishing between His true disciples and imposters such as Judas. The Christian is fully washed in the blood of the Lamb, but as he walks through life he sins occasionally and finds cleansing for sin by confessing it (1 John 1:9). He doesn't have to be washed again in the blood of Christ.