8. Eighthly, In this design of false doctrine Satan is never altogether out; if he cannot thus defile their lives, yet it is a thousand to one but _he obstructs their graces by it_. What greater hindrance can there be to conversion than error! The word of truth is the means by which God, through his Spirit, doth beget us; it is part of that image of God that is implanted in us: it is God’s voice to the soul to awaken it. It cannot then be imagined that God will give the honour of that work to any error; neither can truth take place or have its effect upon a soul forestalled with a contrary falsehood. Falsehood in possession will keep truth at the door. Neither is conversion only hindered by such errors as directly contradict converting truths, but also by collateral non-fundamental errors; as they fill the minds of men with prejudice against those that profess another persuasion, so that for their own beloved error’s sake men will not entertain a warning or conviction from those that dissent from their opinions: they first account them enemies, and then they despise their message. It is no small matter in Satan’s way to have such an obstruction at hand in the grand concern of conversion. Yet this is further serviceable to him, to hinder or weaken the graces of the converted already. If he can set God’s children a-madding upon error, or make them fond of novelties, he will by this means exhaust the vigour and strength of their hearts, so that the substantials of religion will be neglected. For as hurtful plants engross all the moisture and fatness of the earth where they stand, and impoverish it into an inability for the nourishment of those that are of greater worth, so doth error possess itself of the strength of the spirit, and in the meantime neglected graces dwindle into emptiness, and ‘fade as a leaf.’ The most curious questions and opinions that are, contribute nothing to the establishment of the heart; it is only grace that doth that: Heb. xiii. 9, ‘The heart is established with grace,’ and not with disputes about meats; nay, they do grace a prejudice, in that they make it sick and languishing—for to that sense is the original, in 1 Tim. vi. 4, ‘Doting about questions,’ or growing diseased, because of the earnest prosecution of opinions, Νοσῶν περὶ ζητήσεις.