Jesus did not say that everyone must cut off his right hand, but that “if your right hand causes you to sin” in your walk with Him, then it is better to “cut it off.” There are many things that are perfectly legitimate, but if you are going to concentrate on God you cannot do them. Your right hand is one of the best things you have, but Jesus says that if it hinders you in following His precepts, then “cut it off.” The principle taught here is the strictest discipline or lesson that ever hit humankind.
When God changes you through regeneration, giving you new life through spiritual rebirth, your life initially has the characteristic of being maimed. There are a hundred and one things that you dare not do— things that would be sin for you, and would be recognized as sin by those who really know you. But the unspiritual people around you will say, “What’s so wrong with doing that? How absurd you are!” There has never yet been a saint who has not lived a maimed life initially. Yet it is better to enter into life maimed but lovely in God’s sight than to appear lovely to man’s eyes but lame to God’s. At first, Jesus Christ through His Spirit has to restrain you from doing a great many things that may be perfectly right for everyone else but not right for you. Yet, see that you don’t use your restrictions to criticize someone else.
The Christian life is a maimed life initially, but in Matthew 5:48 Jesus gave us the picture of a perfectly well-rounded life— “You shall be perfect, just as your Father in heaven is perfect.”