I think I can paraphrase this bit of prose from Luke quite succinctly like this;
Don’t worry about how sinful or otherwise other people might be. Sort your own life out. Your life is the only one you have direct control over.
Take responsibility for your own being and standing before God. The last little parable of the fig tree Jesus uses to emphasise what he says suggests there is always time to change and bear fruit but that time won’t last forever because eventually the fig tree will be cut down. Of course in the natural course of things we will die.
Nurturing our spiritual lives is what Jesus is alluding to when he talks about putting manure around the tree.
The fig tree is used in the Bible as a symbol of the people of Israel, and of course they always thought more collectively than we instinctively do but taking into account our more individualistic frame of mind I invite you to think of yourself as the fig tree or actually as any fruit tree you like.
Close your eyes and Imagine yourself as any kind of fruit tree. What state are you in?
Are you flourishing? Are you well watered, have you basked in the light, has your tree been pollinated? Will you produce lots of blossom that will produce lots of apples or pears or figs or whatever?
Or is the ground your tree in standing in poor ground, did the rains fail to come, the sun not shine, were you not well fed and watered so your crop will be a bit miserable.
Taking responsibility for the growth of our own tree is a spiritual task that only we can do for ourselves.
Part of that nurture will be coming to church on a Sunday. Part will be time spent in contemplation meditation or prayer. Part will be in taking theology seriously. Theology means just “God talk”. Who is God, what is God, what is the essential nature and character of the divine. Learning and discussing in a more structured and intellectual level is also a constituent part. Does it make any sense at all? Can you defend your faith publically?
The responsibility for each of us precious plants to blossom and grow is primarily our own responsibility but naturally there is always a communal aspect in Christianity. We, each of us has a responsibility to make this space and this community(the church) fertile ground where a person can set down roots and grow. Our communal responsibility is to hold and accept and offer an open space where a person can freely explore their own way of being in the light of God.
To be held in community is a vital human need which when neglected causes something inside to atrophy and sometimes even die and people can turn in on themselves.
To stop that happening, to provide fertile ground for all of our journeys the best place to start is as an individual taking responsibility for our own spiritual development and then also realising our part in our collective responsibility to build a community worthy of the name.