Those to whom Paul writes are still worldly. The Corinthian church is torn by division, disagreements, dissension. This is worldliness. This is the opposite of spiritual. Spiritual people are unselfish as God is unselfish, giving as God gives.
Spiritual people care for others, risk themselves for others.
Spiritual people treat others right. Spirituality has to do with how we get along with others. Spiritual people seek the restore the fallen, to lift up those who have quit. These two things are obvious in the early chapters of 1 Corinthians. Spirituality relates to the spirit of God and how we treat one another.