Matthew 12:1 says, At that time Jesus went on the sabbath day through the corn; and his disciples were an hungred, and began to pluck the ears of corn, and to eat.  At this time, the disciples were with Jesus.  They were passing by a corn field, and they were hungry, so they began to pluck some of the corn.  I guess we could asks why they would pluck someone else's corn, but I believe that it was acceptable to gather a little in that time if a person was hungry.  Now they couldn't gather the whole crop, but just enough to satisfy their hunger.  As God's people, we have a responsibility to feed the hungry and not to worry about the cost.  It really all belongs to God anyway.  Verse two states, But when the Pharisees saw it, they said unto him, Behold, thy disciples do that which is not lawful to do upon the sabbath day.  Since the Pharisees saw them and did not question their right to pluck the corn, but instead questioned their doing so on the Sabbath, we can assume that the plucking was alright.  The Pharisees were again concerned about following the letter of the law, that had been greatly added to, instead of the spirit of the law.  In verse three Jesus asks, But he said unto them, Have ye not read what David did, when he was an hungred, and they that were with him;  Speaking to the Pharisees, Jesus basically asked them if they were familiar with the scripture.  If someone begins to condemn us for our spiritual actions today, they need to make sure that their condemnation is based on what God's word really teaches.  We cannot base our view of the actions of other Christians on tradition or personal views, but must evaluate all, whether we see the action as good or bad, on the teachings of God through the leadership of the Holy Spirit.  Jesus asked the Pharisees if they remembered what David did.  Verse four declares, How he entered into the house of God, and did eat the shewbread, which was not lawful for him to eat, neither for them which were with him, but only for the priests?  David ate the shewbread in the house of God, as did those who were with him.  Under the religious law, they were not entitled to do so, since they were not priests.  We must remember that our status with God is based on our relationship with Him through faith and not by being made righteous by our own actions.  Verse five says, Or have ye not read in the law, how that on the sabbath days the priests in the temple profane the sabbath, and are blameless?  Again, Jesus asked the Pharisees if they had read the law.  In the law, or scripture, the priests work on the sabbath day and are blameless.  Though Jesus did not say it at this time, He is our great High Priest, and we as His followers are a priesthood of believers, so whatever was lawful to a priest is lawful to us.  Even beyond that, we are not judged by the law of God, but by our relationship to Christ.  Verse six declares, But I say unto you, That in this place is one greater than the temple.  Here, Jesus makes an indirect reference to His being greater than the temple.  We do not need to worry about what people do until they have a relationship with Christ, the One Who is greater than the temple and the law.  Verse seven states, But if ye had known what this meaneth, I will have mercy, and not sacrifice, ye would not have condemned the guiltless.  Jesus told the Pharisees, and tells us today, that mercy is more important than sacrifice.  Jesus said the Pharisees did not understand this.  We today must understand that salvation is based on faith in Christ, and not on anything we may sacrifice to God, nor on how well we keep the law.  Faith in the mercy of God in sending Jesus to die for our sins is the only way to salvation.  Verse eight further declares, For the Son of man is Lord even of the sabbath day.  Jesus is the Lord of the Sabbath, so anything that we as His followers do for Him on the sabbath, or Sunday in our case, is lawful.