If all I hear is that I am a son and a saint, I may become flippant about sin and negligent of duty.
However, if I err in the other direction, I may sink into the Slough of Despond. If all I hear is that I am a miserable wretch of a sinner, then I am unlikely to experience the joy of forgiveness: justification, adoption, and the certainty of eternal life.
If all I hear is that I am a servant, then God may become to me an oppressive taskmaster, whose presence is avoided because an awareness of God means still another task added to my already overburdened job description.
You can read the whole thing here.
HT: Carl Trueman