This is a fairly competent bit of theology below but it seeks to apply a broad context to 1 Corinthians 6:19-20. That may be convenient but it ignores the specific context of the passage. The passage is primarily about fornication (illicit sex). Paul regards fornication as unnatural and hence defiling the body.
But it is precisely unnatural things that some Christians object to: Vaccinations, blood transfusions, smoking, consumption of coffee and alcohol etc. A "pure" body would not have those things within it is the conclusion
One can argue about what is unnatural but if illicit sex is unnatural, a fairly broad definition is obviously intended by Paul.
So I think the avoidant stances of some Christians are well justified by the "temple" reference
As governments and businesses implement COVID-19 vaccine mandates, increasing numbers of people are seeking exemption on religious grounds. As such, mainstream social and political discourse has begun to stray into theological territory, with uninspiring results. One common refrain among those seeking exemption from vaccination is the assertion, “My body is a temple”. Given the near ubiquity of this phrase in the sphere of health and wellness, most people are likely to have forgotten that it comes from the apostle Paul.
In 1 Corinthians, Paul writes, “do you not know that your body is a temple of the Holy Spirit within you, which you have from God, and that you are not your own? For you were bought with a price; therefore glorify God in your body.” (1 Corinthians6:19-20) Here, Paul is repeating a refrain from earlier in this same letter: “Do you not know that you are God’s temple and that God’s Spirit dwells in you?” (3:16)
It has become common for Christians to claim that being forced to take the COVID-19 vaccine is a violation of their religious convictions because their body is a temple, and they are commanded to keep it pure. They make this argument for a variety of reasons. For example, some believe the vaccine has dangerous side-effects; others think it contains microchips; and some have suggested that it can alter your DNA or cause infertility. Each of these, it seems, would violate the purity of their bodily temple, making it unsuitable as a vessel for the Holy Spirit.
It is worth stating unambiguously that there is no evidence that any of these things are true of the available COVID vaccines, beyond some extremely rare and typically mild side-effects. Nonetheless, the question I would like to consider is whether a vaccine could, in theory, go against Paul’s exhortation in this passage.
“A temple of the Holy Spirit”
Let’s begin with Paul’s first letter to the Corinthians itself. Most commentators agree that the purpose of the letter is to urge unity among the Christians in Corinth. In the third chapter, Paul addresses the elephant in the room. The Corinthians have been drawing lines of separation based on who brought them to the faith. Some have been saying “I belong to Apollos” (which is to say, “I’m a member of Apollos’s faction”), while others say “I belong to Paul”. And yet, Paul sees no reason for this to cause strife: “We are God’s servants, working together; you are … God’s building.” Paul and Apollos cooperate in building on the foundation that Christ himself laid. And this leads him to ask: “Do you not know that you are God’s temple and that God’s Spirit dwells in you? If anyone destroys God’s temple, God will destroy that person” (3:16-17).
Paul says that the Corinthian church as a whole is God’s temple, and those who cause division among them are threatening to destroy it. Paul’s warning is not about the pollution of their individual physical bodies, nor any threat from outside. He is warning them about the effect of their own divisive actions on the community. Paul follows this with fitting words for our time: “So let no one boast about human leaders” (3:21).
Three chapters later, Paul returns to the image of the temple, this time with individual Christians in view. Now he is discussing specific sinful habits that are causing division among the Corinthians. In particular, he commands them not to engage the services of prostitutes, and in general to “shun fornication” (6:18). And why should they do this? Because their body is a temple of the Holy Spirit (6:19). Far from suggesting that the Holy Spirit cannot dwell in a body that is physically contaminated by illness, microchips, medicines, or other substances, Paul is urging them to keep themselves free from sin.
Paul is repeating a central theme of the New Testament, which is that the purity laws found in the Torah no longer hold for those who are in Christ, because he has fulfilled them (Matthew 5:17). Christian notions of purity are not about food laws and physical cleanliness, but about the heart. As Jesus explains, “it is not what goes into the mouth that defiles a person, but what comes out of the mouth.” He goes on to explain that “out of the heart come evil thoughts, murder, adultery, sexual immorality, theft, false witness, slander. These are what defile a person.” (Matthew 15:11, 19-20)
Paul has something similar in view in his second letter to the Corinthians: “let us cleanse ourselves from every defilement of body and of spirit, making holiness perfect in the fear of God” (2 Corinthians 7:1). He explains that the sins of sexual immorality and idolatry defile the body and the spirit, and he urges them to free themselves of it (see also 1 Thessalonians 5:19-24).
Grounds for exemption?
It is worth considering the implications of Paul’s words if they did mean what those seeking exemptions from the COVID-19 vaccine take them to mean. If the Holy Spirit cannot dwell in a body that has been contaminated by chemicals or debilitated by injury (let alone in a body injected with a safe and effective vaccine), then countless people who have fallen victim to natural or manmade disasters would be bereft of the presence of God. Similarly, if physical cleanliness was in view, then surely the COVID-19 virus itself would do at least as much to contaminate one’s body. After all, natural illness is one of the main causes of impurity in Leviticus.
Furthermore, it is central to the Christian faith that we may well be called to sacrifice our bodies for the sake of others (see John 15:13; Philippians 2:3-4; 1 John 3:16). We witness this most acutely on the cross. Jesus’s body was made impure by his crucifixion — in fact, that’s a considerable part of the point. It is worth repeating that there is no reason to think that receiving a COVID-19 vaccine involves bodily sacrifice. Regardless, the theological principles here do not support those seeking exemptions. There is no Christian belief that the body must be kept free from physical contamination in order to be a fitting vessel of the Holy Spirit.
In reality, what those seeking exemptions are arguing is that they believe the vaccine will harm them, and therefore they shouldn’t be forced to take it. There is nothing distinctly religious about the fear of bodily harm involved in vaccine hesitancy. In general, non-religious people fear bodily harm just as much. This should lead us to question why religious exemption is being sought here. The answer, it would seem, is that there is a long-standing precedent for exempting religious communities from government mandates, so people have reached for religious exemption as a ready-made solution for their fears.
This should give Christians pause. Freedom of religion plays an important role in our society, but it is always in danger of being abused and misused. As Christians, we have a vested interest in ensuring that it is not. If our non-Christian neighbours come to see us as people who think the rules don’t apply to us, or as people for whom the well-being of the wider community is irrelevant, their tolerance for our beliefs is likely to wane. At the same time, if our theological beliefs are sacred, then we should be unwilling to let people twist them for political or legal purposes. The truth of what Paul wrote should matter more to us than the use to which it can be put in court. A vaccine cannot go against Paul’s exhortation, because it is not what goes into us that defiles us, but the sin that emerges from our hearts.
Paul warns the Corinthians not to deceive themselves, but to have true wisdom (1 Corinthians3:18). James describes such wisdom as “first pure, then peaceable, gentle, willing to yield, full of mercy and good fruits, without a trace of partiality or hypocrisy” (James 3:17). Especially in the United States, the belligerent response on the part of many Christians to the public health efforts of the past two years looks rather different from this vision of wisdom. If we take Paul’s words seriously, our main concern shouldn’t be the physical purity of our own bodies, but the purity of our witness to the world around us. After all, the Christian witness has always been grounded, first and foremost, not in individual political liberty, but in self-sacrifice for the well-being of others.