Why did Jesus say that "Mary has chosen the better part"? Why did Jesus tell Martha, who was serving the Lord and making preparations, that Mary had "chosen what is better"?


  As Jesus and his disciples were on their way, he came to a village
  where a woman named Martha opened her home to him. She had a sister
  called Mary, who sat at the Lord’s feet listening to what he said. But
  Martha was distracted by all the preparations that had to be made. She
  came to him and asked, "Lord, don’t you care that my sister has left
  me to do the work by myself? Tell her to help me!"
  
  "Martha, Martha," the Lord answered, "you are worried and upset about
  many things, but few things are needed-or indeed only one. Mary has
  chosen what is better, and it will not be taken away from her." (Luke 10:38-42)
But seek ye first the kingdom of God, and his righteousness; and all
  these things shall be added unto you.
  
  Matthew 6:33


This is what Mary was doing. Although what Martha was doing was not wrong, her focus was on those things and not on Jesus. Many people can get so caught up in church and completely forget about Jesus. Fixing things, making sure everything is ok, cooking, etc... They're not bad things, but when you leave Jesus aside, you are leaving salvation aside. We must seek Him first, everything else will be added on. This is what Mary did.