[AQ]

If the lens you use on the camera is horizontal then any verticals in a building will stay vertical (near enough) you will of course get a lot of foreground in any picture taken that way and you will have to be further away from the building to get it all in.

If you tilt the lens upwards, as most of us do, the verticals will appear to converge. The more you tilt the more the convergence. Also the wider angle the lens is the more convergence you see as in Stephano's first picture and less so in that link you posted of the church. In that the verticals are still not vertical in the frame.

This is not a fault of the lens just the way the laws of optics work.

You only have three options

You can use the expensive tilt and shift lenses, as already mentioned, to get a picture in the camera with the verticals and horizontals "square"

Keep the camera horizontal and far enough away to get all the building in. Not always possible in cities etc

Correct the image something like Photoshop again as Stephano showed.