There is an overlap between prophesying and exhorting. An overlap refers to the state of having common characteristics. Prophesying and exhorting share certain common components. Paul wrote, “The one who prophesies speaks to people for their upbuilding and encouragement and consolation” (1 Cor. 14:3). Prophesying includes encouraging and comforting. Exhorting includes encouraging and comforting. Thus, the gift of prophesying may involve the gift of exhorting.
The overlap between two special abilities means one thing. Paul was not thinking in terms of a set of clearly defined ministries. We think of ministry in terms of clearly defined tasks with clearly defined job descriptions. (Dunn) But for Paul, the important thing is to use your abilities according to the ability of the Spirit.
Do you have the ability to urge someone? Do you have the ability to comfort and encourage people? You have the gift of exhortation! That is how you are to function in the body of Christ.