1: Our bodies are temples of the Holy Spirit. What does that mean? It means that our bodies are holy and set-apart. Different from the world. And that means that they should be cherished and valued, not just because you want to one day give your husband a precious gift, but because God gave this gift to you and you should give it back to Him untarnished and pure. That you should keep it set apart for Him, instead of showing everything to the world. Instead of putting yourself on display because you feel that you have “Christian liberty.”
2: God has commanded it. While the Bible doesn’t give us step by step details of how we’re supposed to dress modestly, it does say that we’re supposed to be modest. We as Christians are called to obey God’s Word no matter what, and by disregarding God’s command we’re sinning.
3: Because you love the Lord your God. If you can’t be modest for your brothers in Christ, then do it simply because God says so and you love Him.
4: Because we have to set an example to the younger girls around us. They are looking at us trying to figure out what’s what and if we go around in something like a bikini, what are we telling them? That our bodies are nothing more than eye-candy for people to lust after. That we aren’t worth more.