...if it's not from God, it's not for us. See, Satan is in the business of half-truths and little white lies. They seem fine to us if we aren't paying attention, but in reality, they are very destructive.
For example, God gave us the gift of marriage. But Satan likes to twist it, telling such lies like "But it's love", "God is love", and "God just wants you to be happy". And that is where we end up with all kinds of ridiculous distortions of marriage, like homosexuality and polygamy (and even living together before marriage), for example. God is very clear on the fact that marriage is for one man and one woman, but when you're listening to Satan, it doesn't always seem that way.
In the Garden of Eden, Satan twisted God's words when he tempted Eve. He asked her, "Did God really say, 'You must not eat from any tree in the garden'?" (Gen 3:1). Well, we know that God told Adam and Eve that they could eat from "any tree in the garden" except "the tree of the knowledge of good and evil" (Gen 2:16-17). See how Satan twisted God's words to suit himself?
Okay, so you probably fall into the category of lies from Satan on a much smaller scale than something like polygamy. Maybe you are considering whether to pursue a relationship with a girl or guy who isn't a Christian. And Satan's telling you that you should totally be a missionary to them and that a good way to do that is to date them. Dating and relationships are good things from God, but only in the right context. Or maybe you're wondering about something even simpler, like music, which is a gift from God. But let's say you like a certain song and it's not explicit, but it's not clean, either, if you know what I mean. Music is from God, but Satan often uses it in just horrible ways. Keep a lookout for things like that. Do you really want that song playing in your head, on your iPod, in your car?
Another example: There are times when we are vulnerable and need to keep a guard up for safety. I'll explain it a different way: My college has a guard shack at the front entrance. During the day, the guards will wave at whoever comes into the campus. But at dusk, when it starts getting dark and the college itself becomes vulnerable, the guards typically stop cars coming in to make sure they belong here. When are vulnerable to Satan's voice, maybe when we're alone, or around people of the opposite gender, or surrounded by people who seem to have it all together and look like they're models... We must guard our hearts.
Believe me, it's hard to distinguish God's voice from Satan's voice sometimes. But here's something my stepdad taught me: God wants what's best for me even when I don't. In sin, I typically desire what feels good or what makes me look better to others, but God, in his love, desires (and knows) what is the best not only for me and my life, but also for the lives of those around me. And, this is awesome, "the best thing" may not be the easiest thing. In fact, God often uses difficult situations to grow us and mold us to become more like Him. Trust God's timing and God's voice and make those difficult decisions he is leading you towards. You may or not may not see an immediate result, but you will feel peace. Peace from the Holy Spirit.
No matter how good it is, if it's not from God, it's not for us.
For we are not fighting against flesh-and-blood enemies, but against evil rulers and authorities of the unseen world, against mighty powers in this dark world, and against evil spirits in the heavenly places.
