Mark 2:16-20

Mark 2:16 (KJB)
And when the scribes and Pharisees saw him eat with publicans and sinners, they said unto his disciples, How is it that he eateth and drinketh with publicans and sinners?

No doubt the Pharisees had seen this group enter the house of Matthew and it would have seemed normal to them since all the guests were publicans and sinners but then they saw Jesus eating with them and the disciples were questioned by them. They wanted to know why Jesus was associating, and even worse, being seen in public with this crowd. They wanted to know why He was eating with them? They did not know that Matthew had just become a disciple and wanted to tell all his friends and co-workers the good news. (Mat 21:31 KJV) Whether of them twain did the will of his father? They say unto him, The first. Jesus saith unto them, Verily I say unto you, That the publicans and the harlots go into the kingdom of God before you. The Pharisees because of their arrogance and pride had sentenced themselves to eternal damnation.

Mark 2:17 (KJB)
When Jesus heard it, he saith unto them, They that are whole have no need of the physician, but they that are sick: I came not to call the righteous, but sinners to repentance.

Then Jesus overheard their question and responded quickly. He used the example of if a person is healthy, why would they go to a doctor? Only when a person becomes sick should they go see a doctor. The basic premise here is that those who are sick need a doctor just as those who are sinners need a Savior. In other words, everyone needs a Savior including the Pharisees. The Pharisees had placed ritual and ceremony above everything, even to the excluding of having mercy upon someone. The whole essence of the ministry of Jesus was to have mercy on the sinners who became saved. He came to call them to repentance, that is, to salvation. When Jesus speaks about not calling the righteous, he may have those in mind who are already saved and He may have implied that those who are “self-righteous” and do not think they need a Savior. Until the Lord opens their spiritual eyes or ears, they will continue to walk around in spiritual ignorance of the fact they too are in need of a Savior.

Mark 2:18 (KJB)
And the disciples of John and of the Pharisees used to fast: and they come and say unto him, Why do the disciples of John and of the Pharisees fast, but thy disciples fast not?

Apparently even after John was thrown into prison, some of his disciples had stayed together in a group. This little feast in Matthew’s house had probably been planned on a day of fasting when both the Pharisees and the disciples of John would fast. The Pharisees would fast on Monday and Thursday. So this may have occurred on one of those days. The disciples of John had approached Jesus directly on the question of fasting. They wanted to know why they and the Pharisees fast but His disciples do not fast. It is the difference between freedom in Christ and a religious system.

Mark 2:19 (KJB)
And Jesus said unto them, Can the children of the bridechamber fast, while the bridegroom is with them? as long as they have the bridegroom with them, they cannot fast.

They normal length of a Jewish wedding lasted seven days and during that time, the guests were normally excused from the more serious religious obligations. (Isa 54:5 KJV) For thy Maker is thine husband; the LORD of hosts is his name; and thy Redeemer the Holy One of Israel; The God of the whole earth shall he be called. The time for fasting in a preparatory sense has passed because now is the time of fulfillment. Jesus will be the husband and the body of believers will be the bride of Christ. This is why there is no mourning or fasting on the part of the disciples because the time of fulfillment of all the prophecies of the past has come. Fasting in the presence of the bridegroom would show a sadness or a displeasure concerning the wedding and may be considered an insult. A wedding is a time of joy and not for sadness.

Mark 2:20 (KJB)
But the days will come, when the bridegroom shall be taken away from them, and then shall they fast in those days.

Jesus then states there will come a time when the disciples will fast. This will be the time when He is taken from them for three days for the crucifixion until the resurrection. During those days, there would be a time of mourning and fasting. Fasting was never a part of any requirement. If a Christian fasted, it was between them and God. During the years of the New Testament there would be fasting by the church but not by requirement, it would be voluntary. (Acts 13:2-4 KJV) As they ministered to the Lord, and fasted, the Holy Ghost said, Separate me Barnabas and Saul for the work whereunto I have called them. {3} And when they had fasted and prayed, and laid their hands on them, they sent them away. {4} So they, being sent forth by the Holy Ghost, departed unto Seleucia; and from thence they sailed to Cyprus.