I want to emphasize a two letter word in verse 31. That is the word "if". The phrase is if you continue in my word, you are my disciples of Christ? The word continues is a very importatnt word in the vocabulary of the Bible. We can call ourselves Christians but not know where we really are. Then we have a beautiful word of Jesus. "Ye shall know the truth and the truth shall make you free." Whe I was a boy a man from a well known false cult came often and talked with my father. He brought a magazine and on it was the words, "The truth shall set you free." Then Jesus said in John 14:6, "I am the Truth". There is freedom in knowing the One who personifies the Truth.
These verses bring out the true fact that there are two families of people on the earth. The family of God, belonging to and being set free by Jesus Christ. Then there is the family of the devil consisting of those who do not know Him at all.
We have another phrase by Jesus worth looking at. That is verse 36. "If the Son (Jesus) shall make you free, Ye shall be free indeed." This is another "if" in the words of Jesus. I am thankful I can call myself a free man in Christ.