Which preposition to use with christianizing

of Occurrences 3%

"I've always said," he exclaimed, "that if the other business men of America had as much sense as the tobacco folks they would hasten the Christianizing of China by many a year.

of Occurrences 1%

In consequence of this engagement of the Wesleys, the General deemed it highly proper to visit their venerable and excellent parents at Epworth, not only to confirm their consent, but to communicate to them such information as should interest them strongly in every measure which aimed at the instruction, civilization, and christianizing of the natives of Georgia, from whom he and the new settlers had met so kind a reception.

Which preposition to use with  christianizing