For a stone of stumbling and for a rock of offence.

A stepping-stone can be a stumbling block if we can't see it until after we have tripped over it.

But not as the offence, so also is the free gift. For if through the offence of one many be dead, much more the grace of God, and the gift by grace, which is by one man, Jesus Christ, hath abounded unto many.

Have I committed an offence in abasing myself that ye might be exalted, because I have preached to you the gospel of God freely? / I robbed other churches, taking wages of them, to do you service.

The depths have covered them: they sank into the bottom as a stone.

And he beheld them, and said, What is this then that is written, The stone which the builders rejected, the same is become the head of the corner? / Whosoever shall fall upon that stone shall be broken; but on whomsoever it shall fall, it will grind him to powder.