Pasteur’s work saved millions of lives. It was because of him surgeons started to wash their hands before operating.
But he was also an ardent Christian throughout his life. The Literary Digest of 18 October 1902 gives this statement from Pasteur that he prayed while he worked:
Posterity will one day laugh at the foolishness of modern materialistic philosophers. The more I study nature, the more I stand amazed at the work of the Creator. I pray while I am engaged at my work in the laboratory.
His son-in-law wrote in a biography of him:
Absolute faith in God and in Eternity, and a conviction that the power for good given to us in this world will be continued beyond it, were feelings which pervaded his whole life; the virtues of the gospel had ever been present to him. Full of respect for the form of religion which had been that of his forefathers, he came simply to it and naturally for spiritual help in these last weeks of his life.