From The Crucifixion Of Ministry by Andrew Purves:

Only the ministry of Jesus is redemptive. No amount of religiously motivated helpfulness or niceness can fill in for the redemptive ministry of Jesus Christ. The danger for us and especially or our parishioners comes when we insist on displacing the ministry of Jesus with our own ministries. When that happens our ministries must be crucified.
Books and classes on the ministry of the church must have Jesus Christ and his ministry at their core. But they must have him at their core in a very specific sense, namely to teach who he is and what it means that he had a ministry yesterday, that in the power of the Spirit he has a ministry today, and that he will have a ministry tomorrow when he comes again.