Someone who does not love sinners, cannot be in the right mind to love to preach the Gospel.
One cannot ask someone who does not love to preach the Gospel to organize a rally event, whether he/she has the status of a pastor/preacher or not. Because that would mean asking someone who does not love sinners to do the crucial commission.
Therefore, one must discern, when co-working with anyone in our Lord's great commission, that the person shows more proof of labor in the Gospel himself/herself than proof of labor in the labor of the Gospel.