Mar 9:45 And if thy foot offend thee, cut it off:

Mar 9:45 And if your foot offends you, cut it off: it is better for you to enter halt into life, than having two feet to be cast into hell, into the fire that never shall be quenched:
Alternative: And if your foot causes you to stumble, cut it off. It is better for you to go through life limping than having two feet that let you fall into the trash heap and the eternal funeral pyre.

This is the second iteration of verse. The first time, Christ warns us of our hands, which is the symbol for our relationships with others. Here, the foot is the symbol for our physical bodies. Next is the eye, which is the symbol for our mental world.

In the underlying Greek, besides the change from "hand" to "foot," there is another slight change in vocabulary that represents the fun plays on words Christ likes to make. With one leg we "enter into life," but with two legs, we "fall" into the trash heap.  In the previous Mark 9:43, the word used is aperchomai, which is the idea of "departing" as in leaving from a relationship, which is what the hand symbolized.  But here, that word is changed to ballo, which means "to let fall," making a bigger joke on the "stumbling" (skandalizô) part of the verse, adding the idea of falling at the end. The foot symbolizes the physical part of life, so "falling" is a stronger analogy than simply "departing."

The point here is that physical handicaps are meaningless in terms of the bigger picture. The purpose of life is making spiritual progress. Our physical abilities or lack of them dictate what we can do in terms of functioning in this world, but they are immaterial in term of our physical progress. What we need to avoid is wasting our lives. Each age is unique and special. The end of the age is the accounting for our progress or lack of it.

Our failure to make progress in this life sticks with us forever but that doesn;t mean that we cannot make progress when we fail.

"Offend" is from skandalizô (skandalizo), which means "to cause to stumble," "to give offense," and "to scandalize."

"Cut off" is from apokoptô (apokopto), which means "cut off," "hew off," "exclude from reckoning," "cut short," "bring to an abrupt close," and "smite in the breast from mourning."

"Better" is from kalos (kalos), which means "beautiful," "good," "of fine quality," "noble," and "honorable." It is most often translated as "good" juxtaposed with "evil" in the New Testament, but the two ideas are closer to "wonderful" and "worthless," "noble" and "base."

"Enter into" is from eiserchomai (eiserchomai), which means both "to go into," "to come in," "to enter," "to enter an office," "to enter a charge," (as in court) and "to come into one's mind."

"Life" is from  zoê (zoe), which means "living," "substance," "property," "existence," and, incidentally, "the scum on milk." It has the sense of how we say "make a living" to mean property. Homer used it more to mean the opposite of death.

"Halt" is from chôlos, which means "lame," "limping," and "defective." A very similar word, cholos, which means "gall," "bitter," "angry," and "wrathful."

"Caste" is from ballo, which means "to throw," "to let fall," "to put," "to pour," or "to caste."

"Hell" is geenna (geenna) which is Greek for Gehenna, the valley of Hinnom (the Hebrew word), south of Jerusalem where trash, including diseased animals and human corpses was burned. A constant fires was kept burning there. This area was originally where children were sacrificed to Baal, and Baal (Beelzebub, "lord of the flies"), which is the name that Christ says others call him as the personification of evil.

"Fire" is from pur (pyr), which means "fire," "sacrificial fire," "funeral fire," "hearth-fire," "lightning," "the light of torches," and "heat of fever."

"Never shall be quenched" is from asbestos (asbestos), which means"unquenchable," and "inextinguishable."