Romans 15:20

yea [yes, so full was the spiritual power imparted to me that I thought it an honor and recognition due to my office and to those powers to use them only on the hard, unbroken soil of utterly unenlightened paganism], making it my aim so to preach the gospel, not where Christ was already named, that I might not build upon another man's foundation [Had Paul done otherwise he would have used his supreme powers as though they were secondary, and he would have been choosing the easy tasks, leaving to others those harder undertakings for which Christ was hourly fitting and equipping him (1 Corinthians 3:10; Ephesians 2:20; 2 Corinthians 10:12-16). It ill becomes a ten-talent man to seek a one-talent position. The pressing needs of the field also forbade the waste of time in resowing. Had Paul's example been followed, what needless overlapping of missionary effort might have been avoided. Sectarianism has caused and committed this sin, and it has been especially reprehensible where it has been done to foster points of difference which are matters of indifference, as is the case where factions of the same sect compete in the same field];