The "secret handshake" is a symbol of a covenant made with God. Keeping the covenant is what is essential, not the symbol.
Then you've a VERSE to show this; right?
I think the thing to remember is that Christ let misunderstandings lie . . . he was often misunderstood and often did not explain the misunderstanding. See the comical interchanges with Christ and Nicodemus, Christ and the Samaritan woman, Christ and the official whose son was sick in John 2, 3, and 4. Look at some of the conversations with the Pharisees, particularly when he stood accused. He didn’t explain himself to those he did not want to.
My point is this. Scriptural understanding comes from the Holy Spirit, the plain words of scripture, and from your fellow Christians. It is critical to read the Bible in whole, not in part, and to not let understanding run away from you based on one verse. For example, remember the rich young man that asked Christ what he had to do to be saved? Christ answered him in part at first and said follow the law. “Which law?” the rich man asked, and Christ named some of the 10 commandments, but not all. The young man asked what else he had to do. Christ said sell all you have, give it to the poor and follow me. Which of these was the full answer? Must we sell all we have and follow Christ? Must we only obey those commandments Christ named in this one exchange to do God’s will?