"And so I have made it my aim to preach the gospel, where Christ was not named, lest I should build on another man's foundation.” Romans 15:20

Paul is not mandating only one way to do ministry. He, as an evangelist, expresses his personal philosophy of how his ministry would be conducted. Paul did not want to follow the itinerary of another’s evangelist efforts, but like a pioneering missionary, take the gospel to virgin areas where it had never been heard. For pastor-teachers, building on an evangelist's soul-winning efforts is an essential part of their ministry. It is common in Christian work to build on others' foundations. Are you laying the kind of spiritual foundation upon which others can build? Many people have to hear the gospel multiple times before believing. Are you telling the gospel story?