What was Titus doing by picking up Paul's mantle?
Titus was continuing the Apostle Paul’s ministry by gathering offerings for the poor saints in person. Paul desired that Titus, who had already begun this work, would also finish in the Corinthians the same grace, completing the collection. Thus picking up Paul’s mantle meant carrying forward that apostolic task of collecting those offerings.
Les explains that Titus picked up the mantle from the Apostle Paul to gather these offerings for the poor saints in person. Paul desired Titus, who had begun, to finish in the Corinthians the same grace also. This collection was not under legal binding or a set of rules and regulations. Rather, the saints were to give under grace, as God prospered them and as the Lord laid it on their hearts. They first gave themselves to the Lord, stepping into God’s saving grace, and then opened themselves to Paul and his ministry. Titus thus carried forward Paul’s apostolic work of gathering the offering.
Insomuch that we desired Titus, that as he had begun, so he would also finish in you the same grace also.