Hold Your Man from 1933 with Clark Gable and Jean Harlow
This is not an easy movie to categorize as it's a full-throttle pre-code story about two grifters - Gable and Harlow - who meet and deny that they are falling in love, but it ends with a Christianity redemption moment delivered by one of the era's most-oppressed people.
At first, after meeting and hooking up, Gable and Harlow act like they kinda don't care about each other and just go on grifting and sort of living together. But you know Harlow cares as when one of Gable's ex-girlfriends shows up, a girl-fight ensues: the ex-girlfriend slaps Harlow who counters with a left jab that knocks the ex back hard...girlfight over, Harlow won.
But it takes much more trouble for Gable and Harlow to see what they mean to each other. When Harlow is sent to a women's reform prison (more dorm-like than prison), she discovers she's pregnant with Gable's baby. Stop there for a second to ponder what 1933 Hollywood has just offered up: Two criminals conceive a baby out of wedlock with the pregnant and still-unwed mother now in prison - holy smokes.
Harlow, because she doesn't want to be "that girl," the kind that gets a man by guilt, keeps this a secret from Gable (she won't wear a bra, but for the important things, the girl does have her values). Meanwhile, not much reform is happening initially to Harlow in prison, but she does befriend a fellow black inmate who is a preacher's daughter.
(Spoiler alerts) And just when all hope looks lost, Gable learns of Harlow's condition and risks his own freedom by coming to see her in prison. After some angry words and confusion and with the police coming to arrest Gable, he and Harlow attempt to get married on the fly with the only preacher available being Harlow's black friend's father who is visiting his daughter that day.
So we have a wonderful moment of Christian salvation as Harlow and Gable want to "legitimize" their baby and give it a chance for a decent life as both of them commit to "going straight." And this is all overseen and encouraged by a black preacher who believes in the kindness-and-forgiveness form of Christianity as it is implied that he knows how unfair and hard life can be. And being black in 1933, we have no doubt that he does.
So, to recap, two street-level criminals have casual sex resulting in a baby that leads to an in-prison spiritual epiphany by a pregnant mom and an on-the-lam father all shepherded by a black preacher with a convict daughter. This is a two-fisted pre-code with a bracing shot of religion. It might not fit in a typical Hollywood box, and it's clunky as heck by today's standards, but give MGM credit for making a gritty movie with a quietly subversive social and racial message wrapped inside a redemption story.
N.B., If you do watch it, look for Gable's line during his impromptu prison wedding to Harlow. With the police bearing down on them, Gable, knowing this will be his only chance to marry a pregnant-with-his-baby Harlow, tries to hurry up the preacher (attempting to conduct a proper marriage ceremony) with this comment, "can't you skip some of it and just marry us?" Who says romance was dead in 1933?