| Mark 7:7Amplified Bible - Classic EditionIn vain (fruitlessly and without profit) do they worship Me, ordering and teaching [to be obeyed] as doctrines the commandments and precepts of men. [Isa. 29:13.]See the chapter | 
I [personally solemnly] warn everyone who listens to the statements of the prophecy [the predictions and the consolations and admonitions pertaining to them] in this book: If anyone shall add anything to them, God will add and lay upon him the plagues (the afflictions and the calamities) that are recorded and described in this book.
Therefore, my beloved brethren, be firm (steadfast), immovable, always abounding in the work of the Lord [always being superior, excelling, doing more than enough in the service of the Lord], knowing and being continually aware that your labor in the Lord is not futile [it is never wasted or to no purpose].