Wherefore let him that thinketh he standeth take heed lest he fall.
So, if you think you are standing firm, be careful that you don't fall!
Ὥστε ὁ δοκῶν ἑστάναι, βλεπέτω μὴ πέσῃ.
Ōste o dokōn estanai, blepetō mē pesē.