I am embarassed by the fact that the only big-name writer who present Christian characters in a favorable light is the Mormon Orson Scott Card. Theodore Judson's first novel Fitzpatrick's War also presents Christians who act and think in terms of their faith. Strongly recommend. Clifford Simak was a practicing Christian. "Cordwainer Smith" a high-church Anglican.
OTOH, a contemptible affectation among some writers (Ben Bova, John Barnes) is to spell the name of Deity with a lower-case g. I usually rectify those snide and petty sneers at the eternal transcendent order when I come across them.
I hate that. I kind of wish there was some sci fi writer who could at least include Christianity in there stories and put in in a positive light.