But one thing is needful: and Mary hath chosen that good part, which shall not be taken away from her. Luke 10:42
The disciple is not above his master: but every one that is perfect shall be as his master. – Luke 6:40
Discipleship is too often forgotten; it is as needful as faith. We are to go into all the world and disciple all nations, baptizing them in the name of the Father, the Son and of the Holy Ghost. A man cannot be saved unless he has become a learner in the school of Christ, and a learner, too, in a practical sense, being willing to practice what he learns. Only he who does the Master’s will knows His doctrines. We are, if we have chosen the good part, sitters at the feet of Jesus, just as Saul of Tarsus sat at the feet of Gamaliel; Christ is to us our great Instructor, and we take the law from His lips. The believer’s position is that of a pupil, and the Lord Jesus is his teacher. Except we be converted and become as little children, we can in no wise enter the kingdom of heaven. Sitting at the feet of Jesus indicates the child-like spirit of true discipleship; and this is the one thing needful: there is no salvation apart from it.
The first duty, indeed, of the student to the tutor is that he be cheerful in accepting, and diligent in retaining, what is taught: in this sense, Mary was really waiting upon Christ in one of His loftiest capacities, namely that of a teacher and prophet in the midst of Israel. In that same spirit, had the Master only intimated it, she would have risen to wash His feet, or anoint His head, or wait at table, as Martha did; but she would, while she was performing these active duties, have continued spiritually in her first posture; she could not, of course, have continued literally sitting at the feet of the Saviour, but her heart would have remained in the condition which that posture indicates. She was in the fittest position for service, for she waited to hear what her Lord would have her to do. We must all be servants, too; as we have been servants of unrighteousness, we must by grace submit ourselves unto the rules of Jesus, and become servants of righteousness, or, else, we miss the one thing that is indispensable for entrance into heaven. ~ C.H. Spurgeon
https://www.blueletterbible.org/comm/spurgeon_charles/sermons/1015.cfm