'Weak' in the Bible

And not being weak in faith, he considered his own body as good as dead, [because he] was approximately a hundred years old, and the deadness of Sarah's womb.

For what [was] impossible for the law, in that it was weak through the flesh, God [did]. [By] sending his own Son in the likeness of sinful flesh and concerning sin, he condemned sin in the flesh,

Now receive the one who is weak in faith, [but] not for quarrels about opinions.

One believes [he may] eat all [things], but the one who is weak eats [only] vegetables.

But we who are strong ought to bear the weaknesses of the weak, and not to please ourselves.