Непостоянны

17 но не име́ют в себе́ ко́рня и непостоя́нны;

17 [but, yet] [never, not] have [at, in, into, of, on] [himself, myself, thyself, to myself, yourself] [origin, root] and непостоянны;

пото́м,

[then, later],

когда́ наста́нет скорбь и́ли гоне́ние за сло́во,

when [come, cometh, coming, it will come, will come] sorrow or persecution [after, around, at, behind, over] [saying, the word, word],

тотчас соблазняются.

immediately [tempted, they are tempted].

And they have no root in themselves,
but endure for a while;
then,
when tribulation or persecution arises on account of the word,
immediately they fall away.
Mark 4:17 ESV

And have no root in themselves,
and so endure but for a time:
afterward,
when affliction or persecution ariseth for the word's sake,
immediately they are offended.
Mark 4:17 KJV