Question: "Should Christian women wear pants?"
Answer: The question about whether Christian women should wear pants or slacks is an issue that is raised about externals when the life of the child of God should rather be about a spiritual relationship based upon our position in Christ as believers. The obedience of a child of God is not measured by what clothing we wear but by our walk in the Spirit (Galatians 5:16).
When looking at “doubtful things," we need to use Scripture in context for the principles that will help us walk as believers, which means considering the dispensation and the whole counsel of God and not taking passages out of context. There is a passage in the Old Testament that speaks about a woman wearing men's clothing: "A woman must not wear men's clothing, nor a man wear women's clothing, for the LORD your God detests anyone who does this" (Deuteronomy 22:5). The context of this passage is the second giving of the law to the nation of Israel as they were poised to enter the Promised Land. Deuteronomy 22:5 is an admonition not to live as a transvestite. This has to do with more than just clothing; it also speaks of a life that emulates in every way those of the opposite sex. Transvestitism was a practice of the Canaanites, and Israel was to consider it an abomination. We take a principle from this and apply it to our lives as believers, but we must use it in the context in which it is given and do so in relation to the dispensation of grace.
The Apostle Paul wrote extensively on the difference between the law and grace in Romans. We are not justified by our adherence to the law, but we are justified by faith in Christ (Romans 3:21-28). The believer in Christ Jesus is "dead" to the constraints of the law. "But now, by dying to what once bound us, we have been released from the law so that we serve in the new way of the Spirit, and not in the old way of the written code" (Romans 7:6). Therefore, a believer does not live by legalism, nor by license, but rather by grace.
What has that to do with a believing woman wearing pants? There is no biblical law that says what a woman should wear or not wear. Rather, the issue is one of modesty. Paul addresses the modesty of women in his first letter to Timothy. "I also want women to dress modestly, with decency and propriety, not with braided hair or gold or pearls or expensive clothes, but with good deeds, appropriate for women who profess to worship God" (1 Timothy 2:9-10). The Greek word translated "modest" is the Greek word kosmios, which is translated twice in the New Testament, once as "modest" in this passage and once as "of good behavior" in 1 Timothy 3:1. It came to mean "well-arranged, seemly, and modest."
The word clothes is the Greek word katastole. The meaning of the word was "to send or to let down or lower." It was primarily a garment that was let down and in that day referred to a stole or a loose outer garment worn by kings and persons of rank. Since we know that Paul was not speaking to people of rank, the context here is simply modest attire, and it does not specify what that entails. Paul addressed this issue here because the women in the church were trying to outdo each other in how they dressed, and the flashier the better. They were losing sight of the things that should adorn a godly woman—humility, sobriety, godliness, and good works. The words "dress modestly" are not used here in the context of specific garments, but rather to being clad in a modest covering. It should not be used to prove a prohibition against wearing pants (also see 1 Peter 3:3-4).
So, the issue is that a woman should wear modest clothing. Whether or not that includes a pair of slacks should be a matter for the woman's own conscience before the LORD. If a woman allows her outward appearance to be the measure of her inward relationship with Christ, she is living under the constraints of legalism. Born-again women are free in Christ to wear whatever modest apparel they choose, and the only judgment they should be under is that of their own conscience. "Everything that does not come from faith is sin" (Romans 14:23). We are not to allow our consciences to be dictated to by legalism and the consciences of others, but by our own relationship with Christ. "I have been crucified with Christ and I no longer live, but Christ lives in me. The life I live in the body, I live by faith in the Son of God, who loved me and gave himself for me" (Galatians 2:20). God will take care of the outward woman if we walk in obedience in the inward woman.