How Do We Know New Testament Instruction Applies To Us?

It might surprise many that some Baptists believe Acts 2:38 teaches Peter’s audience had to be baptized for the remission of sins, but think the passage only applied to the Jews of that day. Of course the very next verse refutes that contention, but their argument brings up a much broader question - how do we know any new testament instruction applies to us? After all, every bit of it was said/written to first century audiences.The principle that God’s law applies equally to everyone helps us out with this problem. Acts 10:34-35 teaches us that “God is no respecter of persons.” In this case, the Good News Translation gets at the meaning well - “God treats everyone on the same basis.” Now if that is true, then the requirements that God placed on the people of the first century will be placed upon us also, since God treats everyone on the same basis. He is not going to make it a sin for a person to do such and such back then (still in the new covenant dispensation of course), but allow us to get by doing that same such and such today. That wouldn’t be fair to those people back then (or us, depending upon how you look at it).And so since God required a sinner in the first century to repent and be baptized for the remission of sins (Acts 2:38, Mark 16:16), you can rest assured that He is going to require the same of a sinner today. And since God required a saint to repent and pray to be forgiven of sin in the first century (Acts 8:22), you can rest assured He requires the same of saints today.Some think the definition for modesty has changed, but if God required the first century Christians to dress a certain way then (I Tim 2:9-10), then we must comply with the equivalent. It is true that in some middle eastern cultures it is better to dress more conservative than what God instructs (I Cor 8, 9:20), but God’s absolute requirements on the subject do not change.This principle that God’s new testament law applies equally to everybody then and everybody today (else God is showing favoritism) is also taught by Gal 3:28 - “There is neither Jew nor Greek, there is neither bond nor free, there is neither male nor female: for ye are all one in Christ Jesus.” If a rule was stated to someone then, that same rule applied to everybody then (regardless of race, gender, or social standing), and the same applies to everybody today (regardless of race, gender, or social standing). There are exceptions to this principle (for example, gender roles bring about a very few different requirements for male and female), but they are just that - exceptions, not the rule.And this principle doesn’t just apply to individuals; it also applies to congregations. For example the book of II Corinthians was written to the church at Corinth, but the example of sacrificial giving by the Macedonians in chapter 8 is not only held out to the Corinthians as a worthy example to emulate, but was held out for all then (Rom 15:26) and for all time - God did not intend for the second letter to the Corinthians to be a private one. The whole point of Eph 2:14-16 is that we can’t be one in Christ if there are different divine laws for different peoples. If we are not bound by the same teaching as the Corinthian saints, then we cannot be the same type of saints as they. And if we are not bound by the same teaching as the Corinthian church, then we cannot be the same type of church as they.When God told the church at Corinth to withdraw from the adulterer (I Cor 5), He is telling us to do the same if we run into the same circumstances. When God told the same congregation that Christians should not take their brothers to law (I Cor 6), then He is telling us the same. When Paul writes that division is to be avoided (I Cor 1), we should accept the admonition personally even though we don’t live in Corinth. One could just as easily argue that the Matt 19:9 divorce law only applies to Jews (since they were the only ones there listening at the moment) as one can argue that the instructions to the Corinthians apply to that church only. One could just as easily argue that the Matt 5:28 lust law only applies to males (since that is who is specifically addressed) as one can argue that instructions to the Corinthians only apply to that congregation.Does it really make sense that Paul would tell the Romans in 16:17 to mark those who “cause divisions and offences contrary to the doctrine … and avoid them,” but there is no need for us to do the same? Is it only wrong for the Galatians to practice the “works of the flesh” list in 5:19-21 (but not for us) since that’s who the book was written to? Do none of God’s instructions to the seven churches in Rev 2-3 apply to us? Or is the truth that it does apply to us because we are striving to be what they were - congregations that belong to the Lord?God gave an order to the church at Corinth in I Cor 16:1ff to take up a collection for the needy Christians of their day. At first glance, it is obvious that the instruction was intended to be more broad that just to Corinth, because the churches in Galatia are given the same order. As we’ve noted, God would be a respecter of persons if the commanded some saints to do something, but allowed others off the hook of that same requirement. Indeed, I Cor 4:17 says that Paul taught the same thing “in every church.” To argue that this collection commandment only applied then because of a specific benevolent need, would be about like arguing that the Eph 4:28 commandment to labor only applied then because of the specific benevolent need mentioned in that particular verse. So congregations should take up a collection for needy saints in our day, and for preaching the gospel (as texts like Phil 4:15-17 authorize). I Cor 14:37 says Paul’s instructions in that book are “the commandments of the Lord.” God doesn’t give orders/commandments to one group of people, but not another. Recommendations (because of special circumstances, I Cor 7:8-9,26) yes, but not commandments. Can you imagine God sending one group of people to everlasting punishment for not doing something that He doesn’t even care if another like group does?Any passage that tells us to “keep” the “word of God” (like Luke 11:28) would tell us that we need to heed the instructions of the new testament. The book of I Corinthians is part of the word of God, so we must “keep it,” that is, we must follow the instructions detailed by the book to the Corinthians. John 8:31 requires us to continue in God’s word. Wouldn’t continuing in God’s word mean that we follow the directions of the new testament as if it were directly addressed to us? James 2:22 encourages us to be “doers of the word.” Wouldn’t that mean we are to do what we find the new testament Christians were doing / supposed to do? I Pet 1:22a requires us to obey the truth in order to be saved; wouldn’t that mean we have to obey the truths found in all 27 books, even though they were not written to us directly?The idea is then that if a congregation today wants to be faithful, then said congregation is going to have to practice the same things we see the congregations of the new testament practicing - God plays no favorites. Anybody that can see I Cor 9:27 (“But I keep under my body, and bring it into subjection: lest that by any means, when I have preached to others, I myself should be a castaway”) applies to all Christians even today though it was only written about Paul, should be able to see the same about other new testament teachings even though they were all specifically written to or about people who lived almost 2000 years ago.Conclusion: Studying the new testament diligently with a view toward carefully emulating Christians and congregations (I Cor 11:1, Phil 4:9) is born from the principle taught by Acts 10:34-35 and Gal 3:28. God expects us to follow the Bible, and following the Bible includes trying to be like those in the Bible who were accepted by God.