Why does God search the heart?

Craigslist advertises that it "provides local classifieds and forums for jobs, housing, for sale, personals, services, local community, and events." It is a powerful search engine. Well, God's search engine is more powerful than Craigslist, Goggle, or the host of other search engines. God "knows the secrets of the heart" (Ps 44:21). Though God at times is said to search our hearts (Ps. 139:1, 23; Prov. 20:27; Jer. 17:10, etc.), God ALREADY knows the hearts of all (Ps. 139:2-6; Isaiah 40:13-14). When the Bible says that God is searching the heart, it is a way of expressing that he knows the past, present, and future of one's heart; he does not have to search for something as if it has been lost or otherwise unknown. God knows what has, is, and will happen with your heart, not to mention Craigslist!

God's knowledge is infinite (Ps. 147:5); eternal (Acts 15:18; Is. 46:10); universal, extending to all persons, times, places and things (Heb. 4:13); perfect, relating to what is past, present and to come. He knows all, infallibly and perpetually (Jer. 10:6,7; Rom. 11:33).