Shared ground
Paul’s point is aimed at food restrictions (the lead-in is 4:3). He argues from creation: what God made is good (explicit: “every created thing of God is good”), so it should not be treated as inherently unfit for eating.
He also adds a clear condition about the eater’s posture: nothing is to be rejected if it is received with thanksgiving (explicit). The focus is not only the food item but the manner of receiving it—welcoming it as a gift from God rather than as something defiling.
Verse 5 gives a second supporting reason (explicit “for”): the food “is sanctified” through “the word of God and prayer” (explicit). Whatever “sanctified” means here, Paul links ordinary eating to God’s speech and to spoken dependence on God.
Where interpretation differs
1) “Every created thing”: food only or everything?
Some read Paul as speaking broadly (all created things are good), with food as the immediate example. Others read it more narrowly as “every kind of food,” because that is the dispute in view.
2) “Sanctified”: what kind of change is meant?
Some take “sanctified” to mean “approved/made acceptable for use” (a status in relation to God). Others hear a stronger sense of “set apart for proper use,” where prayer and God’s word mark the meal as belonging to God.
3) “The word of God”: what does it refer to?
Some interpret it as God’s general speech in Scripture that declares creation good and permits eating. Others think it points to specific Christian teaching or sayings that frame eating as legitimate. In both cases, the idea is that eating is aligned with what God has said.
Why the disagreement exists
Paul uses broad phrases (“every created thing,” “sanctified,” “word of God”) in a short argument. Because he is rebutting a specific food-related problem, readers weigh differently how far to generalize his wording beyond that immediate topic.
What this passage clearly contributes
It grounds an ethic of eating in God as Creator (explicit). It treats rejection of foods as unwarranted when the food is received with thanksgiving (explicit). It also ties the legitimacy of eating to a God-ward frame—God’s word and prayer—so gratitude is not merely internal but expressed in speech to God (explicit: “word… and prayer”; inferred: thanksgiving is enacted verbally).