It is impossible - It cannot but happen. Such is the state of things that "it will be." See these verses explained in the notes at Matthew 18:6-7.

It is impossible but that offenses will come - Such is the corrupt state of the human heart that, notwithstanding all the influences of grace, and the promises of glory, men will continue to sin against God; and his justice must continue to punish. See on Matthew 18:6 (note).

Then said he unto his disciples,.... In the Alexandrian copy, and in "three" of Beza's exemplars it is read, "his disciples"; and so read the Vulgate Latin, and all the Oriental versions; that is, Jesus said to his disciples what follows, as the Syriac and Persic versions express, and the latter reads, he said "again". About the time that he delivered the above parable concerning the rich man and Lazarus, he repeated to his disciples what he had before said to them on another occasion, Matthew 18:7

it is impossible but that offences will come; considering the decree of God, the malice of Satan, the wickedness of men, the corruption both of their principles and practices. The Ethiopic version renders it, "temptation will come"; that which will be trying to the faith of the saints, and a stumblingblock to weak minds, as reproach and persecution, errors, and heresies, and the evil lives of professors:

but woe unto him through whom they come; See Gill on Matthew 18:7

Impossible (ἀνένδεκτον)

Inadmissible. Only here in New Testament. See on it cannot be, Luke 13:33.

Offences

See on offend, Matthew 5:29; and compare on Matthew 16:23.

Then said he unto the disciples, {1} It is impossible but that offences will come: but woe unto him, through whom they come!

(1) The Church is of necessity subject to offences, but the Lord will not suffer them unpunished, if any of the least be offended.

17:1,2 Various Sayings of Christ

SUMMARY OF LUKE 17:

Offenders and Offenses. The Power of Faith. The Ten Lepers Cleansed. The Kingdom of God. The Coming of Christ. Lot's Wife.

It is impossible but that causes of sin will come. See notes on Mt 18:6-7.

17:1 It is impossible but offences will come - And they ever did and do come chiefly by Pharisees, that is, men who trust in themselves that they are righteous, and despise others. Mt 18:6; Mr 9:42.

CHAPTER 17

Lu 17:1-10. Offenses-Faith-Humility.

1, 2. (See Mt 18:6, 7).

17:1-10 It is no abatement of their guilt by whom an offence comes, nor will it lessen their punishment that offences will come. Faith in God's pardoning mercy, will enable us to get over the greatest difficulties in the way of forgiving our brethren. As with God nothing is impossible, so all things are possible to him that can believe. Our Lord showed his disciples their need of deep humility. The Lord has such a property in every creature, as no man can have in another; he cannot be in debt to them for their services, nor do they deserve any return from him.