Often I see on Facebook a request for unspoken prayers. Does God hear and answer unspoken prayers?
If you mean by an “unspoken prayer”, a prayer that is directed from a Christian to heaven from the mind of a man or woman without being audibly spoken, the answer is “yes”. God can hear your prayers without your saying them aloud. We learn this from Hannah in I Samuel 1.
If, in reality, you mean by an “unspoken prayer” a request that Christian friends pray for you in general terms so that God can respond to the specific needs of your life without necessarily revealing all of those needs to the ones who may be praying, the answer is, again, “yes”. Surely God knows all of our needs and certainly, if a friend asks me to pray because some difficult things are going on in her life, I am happy to honor that request. I don’t have to know the details because the Father knows them and can respond in ways that are far superior to any solutions that I might have, even if I knew every detail of my sister’s struggle. Sometimes, women will call such a request an “unspoken prayer request”. They simply mean that the details of their needs are not spoken to those to whom requests are being made.
If you mean, though, by “unspoken prayer”, a nebulous better-felt-than-told sort of heavenward inclination—a wish toward God that you don’t take the time or energy to articulate or speak to the Father—I do not believe we have any promise that he will respond to those wishes. He has asked us to make our requests known to Him with supplications (Phil. 4:6). Would anyone argue that God does not know the needs or wishes of His children without our speaking them? Of course, our Father knows our needs (Matthew 6:32). But He wants us to express, in words, our requests. He also wants us to give Him our thanksgiving. It’s not enough to feel thankful to God, even though He knows our hearts (I Thessalonians 5:17,18). So, if by “unspoken prayer” you mean a wish or feeling that you never express, vocalize or articulate, I do not believe there’s any Biblical evidence that God responds to such a “feeling”, particularly if a person is not humbly relying on the power of Biblical prayer in her life. Since Jesus taught us how to pray in Matthew 6:9ff and Luke 11:2ff, and the pattern clearly includes very specific requests, we should utter, from our hearts, words that, to the best of our human abilities, express our needs before His throne.