The most common are foils, antitheses, and oxymorons. These are characters whose personalities, backgrounds, or ideas contrast with one another.
Curse, bless, me now with your fierce tears, I pray. / Do not go gentle into that good night. / Rage, rage against the dying of the light. / Do not Go Gentle into that.
Here, Thomas is juxtaposing the struggle for life and the acceptance of death. Death is often referred to as darkness and we see that here with the "dying of the light."
When Michael Corleone's son is being baptized, this vision of family love is juxtaposed with violent murders being carried out at Michael's command. This perfectly demonstrates the complex nature of Michael's character.