on. This instance of the
Jews, wretchedly improving their phylacteries to superstitious purposes,
their idolizing of the brazen serpent; and thereby of a cure, turning it
into a plague, a snare, with the like, are sufficient testimonies. And
we see how the papists have abused and adulterated the lawful use of
natural mediums, to the unlawful use of artificial mediums of their own
inventions; images and crucifixes, first to help their memories, and
stir up their devotions in their prayers, and then to pray unto them, as
mediums of divine worship. The more cautious had Christians need be in
the use of those mediums, which either God hath ordained by special
command for the help of our memories, and stirring up of our graces, as
the visible elements in the sacraments; or such natural advantages,
which moral equity allows us for the help of our understandings and
memories in spiritual concernments; such is this, we are now speaking
of; it being the same with the use of books and tables. Tertullian tells
us of a superstitious custom among the ancient Christians, that they
were wont to set up images over their doors and chimneys, to keep
witches when they came into their houses from bewitching their children;
and so by a little kind of witchcraft, prevented witchcraft. But surely,
to set up this covenant, where we might often see and read what
engagements we have laid upon our souls, (and I could heartily wish
Christians would do it at least once a week) it will be an innocent and
warrantable spell, to render the witchery of the flesh, world, and
devil, fruitless and ineffectual upon our spirits, while the soul may
say with David, "Thy vows are upon me, O God: I will render praise unto
Thee."

But _Fifthly_, consider often and seriously, who it is that must uphold
your resolutions; even He that upholds heaven and earth: no less power
will do it; "for you are kept by the power of God through faith unto
salvation." It is God that first gives the resolution, and then must
uphold, and bring it into act; "It is God that worketh in you, both to
will and to do of His good pleasure," and therefore labour, I beseech
you, to do these two things.

_First_, Put all your resolutions into the hands of prayer: David was a
man of an excellent spirit, full of holy resolves. "I will walk in mine
integrity," "And I will keep Thy testimonies." And again, "I have sworn,
and I will perform it, that I will keep Thy righteous judgments." And
yet a