In God, fruitfulness is what counts. For the seed of the Word, for the seed which is the Word, to get anything done in us that he came to do, there has to be singularity in the soil of our hearts. Our soil must be set apart, exclusively, for the growth and fruitfulness of that one seed. It must yield no room nor nutrient for anything else to grow. If our soil is a mixed bag, chunky with rocks, or infested with other kinds of seed, our appearance may seem fine for a time, but over time, our fruitfulness (or fruitlessness) will reveal the unfortunate truth.
Like any farmer planting his fields, when God plants Christ in us, he expects Christ out of us (CICO). For that to happen, nothing can compete with the seed that he's scattered on the soil of our lives. When rocks and weeds compete for the soil with that seed, the seed's growth is stunted and its fruit is nonexistent. God wants an abundant harvest, how can we offer him rock gardens and weed beds?