But one thing is needful: and Mary hath chosen that good part, which shall not be taken away from her.
Note 3 at Lu 10:42: Martha was not wrong in serving Jesus and His disciples. Other women ministered to Jesus in this way (Lu 8:2-3, see note 2 at Mt 8:15) without being corrected. Serving was a good thing, but Martha had put it in the wrong place. Her problem was priorities, not what she was doing.
It was a great honor to have Jesus in her home and to be able to hear His personal words to her household. Martha should have given this the same priority that Mary did. There were physical needs that needed to be met also, but Jesus had already proven that He could even feed people miraculously (the feeding of the 5,000, Joh 6:5-13). There really wasn't anything more important than listening to Jesus.
Just like Martha, many of us today are occupied with things that keep us from hearing the words of Jesus. It is easy to recognize and turn from things that are obviously sin, but even good things that we are involved in must be prioritized so that nothing takes the place of seeking first the kingdom of God (Mt 6:33).