Well meaning Christians can focus their efforts on the spiritual concerns of their own heart.  Richard Baxter addresses this nicely in the following excerpt,

One, and the better, is some religious people who think that their business is only with God and their own hearts, and that if they could spend all their time in meditation, prayer, and such like exercises, it would be the best kind of life on earth…Among us such spend all their time in hearing sermons, and in reading, and meditating and prayer, and such like exercises of religion toward God, if they are but rich enough to live without bodily labor.  And the example of Mary and Martha they think will make this good.

I know that this is no common error.  The wicked are of a far different mind.  And I know no man can do too much to save his soul.  But we may do one sort of our work too much to the neglect of other parts.  We have souls in flesh, and both parts have their proper necessity and work. Mary did somewhat else than hear, though she wisely preferred it in its season.  And no one is made for himself alone.  You feel that religious exercises do you good. But what good is it that you do to others?  I confess a monk’s prayer for others is a good work.  But God will have praying and endeavoring go together, both for yourselves and others.  Merely praying God to relieve the poor, and to teach your children, and instruct the ignorant will not excuse you from relieving, teaching, or instructing them.  Yes, and your own good will best come in by your fullest obedience to God.  Do what he bids you, and he will take care of your salvation.  Your own way may seem best, but will not prove best…Doing good is the surest way of receiving good.  The duties of the first and second table must go together.  He who is not zealous to do good as well as to get good has not the peculiar nature of Christ’s flock (Titus 2:14)