Hosea was a prophet (holy man). The Book of Hosea is in the Bible (Old Testament).
God told Hosea to marry a wife who was not loyal (Hosea 1). Hosea loved his wife. He tried to persuade his wife to remain with him. His wife was not loyal to him. But Hosea still loved her. And he still wanted her to be his wife (Hosea 3).
Hosea's troubles with his wife were like God's troubles with Israel. The people in Israel were not loyal to God. God loved them. But they were very evil. So, God would punish them for their evil deeds. But afterwards, the people from Israel would trust in God again. They would confess their evil deeds to God. God would forgive them. And he would love them again (Hosea 14).