The passage in 1 Tim 4:3-5 has occasioned much abuse by some fringe groups who use it as a pretext for eating toxic materials and poisonous food. Such a practice is equivalent to the "snake handlers" in some places who use Mark 16:18 as a "promise" that people who handle poisonous snakes will not be harmed by them and that such behavior is a sign of divine approval.
Such ideas are quite presumptuous - David prayed a prayer to avoid such ideas:
Ps 19:13 - Keep back your servant also from presumptuous sins; let
them not have dominion over me! Then I shall be blameless, and
innocent of great transgression.
See also 2 Peter 2:10. Albert Barnes expands on this matter - see appendix below.
The passage by Paul in 1 Tim 4:4 appears to be a very sensible rule to prevent the rising tide of Gnosticism (and Judaizers) that declared some food "unclean", etc, but had no basis in either fact or theology.
Thus, Paul is suggesting that all food be recognizes as coming from God and the ultimate provider (perhaps with grace at the meal?) Note the comments of Ellicott:
And nothing to be refused, if it be received with thanksgiving.—Every kind of food and drink may become hateful in the
eyes of the all-pure God if misused, if partaken of without any sense
of gratitude to the Divine giver. But nothing which can be made use of
as food ought to be regarded as unclean or as polluted; every kind of
food is intended for man, the only condition being that whatever is
partaken of should be gratefully received by him as a gift.
APPENDIX - Barnes on 1 Tim 4:4
Apples and peaches were made good, and are still useful and proper as
articles of food; rye and Indian-corn are good, and are admirably
adapted to the support of man and beast, but it does not follow that
all that "man" can make of them is necessarily good. He extracts from
them a poisonous liquid, and then says that "every creature of God is
good, and nothing to be refused." But is this a fair use of this
passage of Scripture? True, they "are" good - they "are" to be
received with gratitude as he made them, and as applied to the uses
for which he designed them; but why apply this passage to prove that a
deleterious beverage, which "man" has extracted from what God has
made, is good also, and good for all the purposes to which it can be
applied? As "God" made these things, they are good. As man perverts
them, it is no longer proper to call them the "creation of God," and
they may be injurious in the highest degree. This passage, therefore,
should not be adduced to vindicate the use of intoxicating drinks. As
employed by the apostle, it had no such reference, nor does it contain
any "principle" which can properly receive any such application.
And nothing to be refused - Nothing that God has made, for the
purposes for which he designed it. The necessity of the case the
"exigency of the passage" - requires this interpretation. It "cannot"
mean that we are not to refuse poison if offered in our food, or that
we are never to refuse food that is to us injurious or offensive; nor
can it anymore mean that we are to receive "all" that may be offered
to us as a beverage. The sense is, that as God made it, and for the
purposes for which he designed it, it is not to be held to be evil;
or, which is the same thing, it is not to be prohibited as if there
were merit in abstaining from it. It is not to be regarded as a
religious duty to abstain from food which God has appointed for the
support of man.