Image's center alignment show in editor, but not when published

Hello,

I am having trouble with centering my images in my posts. When I press the center alignment in the editor my images center, but when I hit publish and check the preview/visit the post on my site the images aligned to the left. I have already tried to fix through the style.css, but it didn’t work. I am not too code savy, but would appreciate any help given as my blog posts will be put on hold until I can figure out how to center these images. The theme I am using is the oblique theme.

Thanks