Jesus did not say that everyone must cut off the right hand, but – If your right hand offends you in your walk with Me, 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, says Jesus, if it hinders you in following His precepts, cut it off. This line of discipline is the sternest one that ever struck mankind.
When God alters a man by regeneration, the characteristic of the life to begin with is that it is maimed. There are a hundred and one things you dare not do, things that to you and in the eyes of the world that knows you are as your right hand and your eye, and the unspiritual person says – Whatever is wrong in that? How absurd you are! There never has been a saint yet who did not have to live a maimed life to start with. But it is better to enter into life maimed and lovely in God’s sight than to be lovely in man’s sight and lame in God’s. In the beginning Jesus Christ by His Spirit has to check you from doing a great many things that may be perfectly right for everyone else but not right for you. See that you do not use your limitations to criticize someone else.
It is a maimed life to begin with, but in v.48 Jesus gives the picture of a perfectly full-orbed life – "Ye shall be perfect, as your heavenly Father is perfect."