A large number of víkingar were recipients of the prima signatio in their non-víking life as traders, farmers, or fishermen before the conversions, and so were at least nominally Christian in order to trade with Christians in other countries. We know, for example, that Þangbrandr biskup came to Iceland on his mission in 997 and gave the prima signatio to a large number of Icelanders in order to facilitate trade and to ease them into Chrisendom.

Unfortunately, we don't have any specific information regarding the views of Christian career víkingar toward their pagan counterparts. That said, though, the conversion took place fairly rapidly and, with a few notable exceptions like the pagan Swedes of Uppland and King Blot-Sweyn/Håkan Röde (if you agree with Adolf Schück) in the late 11th and early 12th centuries, was fairly complete.