How can our work glorify God, even if it’s a job most people don’t even notice?
In the Body
Even in the Old Testament, God forbid sexual immorality like adultery  or having sex outside of marriage. In fact, the penalty was so severe that they were both to be put to death (Lev 20:10), so God doesn’t wink at this type of sin, but what about today? Is sexual immorality more permissible today or in the New Testament since we’re under grace? Jesus said, “I say to you that everyone who divorces his wife, except on the ground of sexual immorality, makes her commit adultery, and whoever marries a divorced woman commits adultery” (Matt 5:32), and there are no conditions attached to that statement like, “unless” or “accept for.” Later, Jesus says, “whoever divorces his wife, except for sexual immorality, and marries another, commits adultery” (Matt 19:9). Even the early church commanded the new believers (Gentiles) to “abstain from the things polluted by idols, and from sexual immorality, and from what has been strangled, and from blood” (Acts 15:20), so sexual immorality has always been sin and you cannot glorify God in your body if your joined to a prostitute, male or female. The Apostle Paul reminds us that we “were bought with a price. So glorify God in your body” (1st Cor 6:20), plainly showing we can fail to glorify Him if we are involved in sexual immorality.
Our life is like being under a microscope if you have professed faith publicly in Christ. Of course, some people may never know if you’ve never told anyone, but that’s rare I think and it skirts very closely to their denying Jesus before others. This would be a sin of silence where one never speaks to anyone about their faith and most certainly never in public, but that is not what the Christians I know are like. There may be some who profess it but may not live like it, and that might even be worse, so since we “were bought with a price; do not become bondservants of men” (1st Cor 7:23). Prior to my conversion, I was a slave to sin because we are slave of whomever or whatever we obey, and for humanity, that was sin, but for those who’ve trusted in Christ, we “were slaves of sin [but] you were free in regard to righteousness” (Rom 6:20), so we ought to be obeying our Master, the Lord Jesus Christ and not be slaves of sin. The reason being, “if you present yourselves to anyone as obedient slaves, you are slaves of the one whom you obey, either of sin, which leads to death, or of obedience, which leads to righteousness” (Rom 6:16)? Being obedient slaves to Christ glorifies God while here on earth.
A person’s work ethic is very important to God….more so than to the employer, and even in the Old Testament, we find it taught that “Whatever your hand finds to do, do it with your might” (Eccl 9:10a), while the Apostle Paul  writes, “Whatever you do, work heartily, as for the Lord and not for men” (Col 3:23), and your greatest inheritance isn’t your 401k, but “knowing that from the Lord you will receive the inheritance as your reward. You are serving the Lord Christ” (Col 3:24), but serving with the knowledge that with God, “there is no partiality” (Gal 3:25b). The teaching that those in authority are those ordained by God is not new. The Apostle Paul says we should “Pay to all what is owed to them: taxes to whom taxes are owed, revenue to whom revenue is owed, respect to whom respect is owed, honor to whom honor is owed” (Rom 13:7). Respect is treating someone like you’d like to be treated, even if you didn’t deserve it. Honoring someone that is less than honorable is a hard thing to do, but it is a godly thing to do.
In the World
The Bible reveals that the heavens declare God’s glory, almost as if they were pouring out speech (Psalm 19:1-2), and that the creation itself shows that we are without excuse if we deny God’s existence (Rom 1:20). All we do when denying God’s existence is suppressing the natural revelation of God (Rom 1:18). Whatever a believer does in life should be focused on glorifying God in it. This includes the way the talk, they look, the way they treat others, and what their work ethic is like. We have to be in the world, but that doesn’t mean we should be of the world. There should be a clear distinction in the believer’s life that there is no doubt that the person is a Christ-follower. People’s conversations are different around them. All the dirty jokes are far and fewer between, and it is obvious when they speak to a Christian in public than when they speak to their friends or co-workers. The Christian, at least, ought to be different. We are told to come out of her or the world’s way of life so that we don’t partake of her sins (Rev 18:20). Paul writes, “do not become partners with them; for at one time you were darkness, but now you are light in the Lord. Walk as children of light” (Eph 5:7-8), and “Take no part in the unfruitful works of darkness, but instead expose them. For it is shameful even to speak of the things that they do in secret” (Eph 5:11-12).
Clearly we can glorify God in our lives by what we say and do and how we treat others and what our work ethic is, but also in the way that we point all things to God. Always give God all the glory and that will keep you humble. When someone compliments me, I point them back to God, because anything I have or anything I’ve done I received from God (1st Cor 4:7), and what I brought to God was the sum total of zero! Whatever it is we do, if it does not glorify God, we are wasting our time and resources. I’m not saying you can’t have fun and enjoy life, but in the way we live, we can either glorify God or bring shame upon the cause of Christ. Either way, God will hold us accountable.
More reading for you: How Should I Deal with Sin in my Workplace? 
Resource – Scripture quotations are from The Holy Bible, English Standard Version® (ESV®), Crossway Bibles. (2007). ESV: Study Bible : English standard version. Wheaton, Ill: Crossway Bibles. Used by permission. All rights reserved.