Genesis 38:12 says, And in process of time the daughter of Shuah Judah’s wife died; and Judah was comforted, and went up unto his sheepshearers to Timnath, he and his friend Hirah the Adullamite.  Judah's wife died.  We are not told how long they had been married when this happened.  Matthew Henry said that Judah went up to his sheep shearers for a time of merriment after he buried his wife and was comforted.  We do know that life goes on after the death of a spouse, but a person may not be thinking as clearly as they should for awhile.  Verse thirteen states, And it was told Tamar, saying, Behold thy father in law goeth up to Timnath to shear his sheep.  Someone told Tamar that Judah had left.  We are not told how much time had passed since the death of her second husband, but she may have felt that Judah was not going to honor his promise to her to give his youngest son as her husband.  Matthew Henry says that some people believe that Tamar had accepted God as her God and wanted to possibly be in the lineage of the Messiah, which she was.  Still for whatever reason, she devised a plan to have a child with Judah.  Again, I don't believe that God wants us to use deception to accomplish His will, though He may sometimes work His will in spite of our deceptions.  Verse fourteen declares, And she put her widow’s garments off from her, and covered her with a vail, and wrapped herself, and sat in an open place, which is by the way to Timnath; for she saw that Shelah was grown, and she was not given unto him to wife.  Tamar saw that Shelah was grown and Judah had not fulfilled his promise to her, so she devised her own plan.  She put away her mourning clothes and dressed as a harlot and set in an open place on the way to Timnath, where she evidently knew that she would encounter Judah.  Verse fifteen adds, When Judah saw her, he thought her to be an harlot; because she had covered her face.  Judah saw her and didn't recognize her, possibly because he had simply dismissed her as a harlot.  He definitely was not looking at her with kindness and understanding, but simply as someone to be used.  When we encounter people who are doing bad things, we cannot just dismiss them as someone to be used or ignored.  Verse sixteen states, And he turned unto her by the way, and said, Go to, I pray thee, let me come in unto thee; (for he knew not that she was his daughter in law.) And she said, What wilt thou give me, that thou mayest come in unto me?  Judah asked Tamar to come to him for the purpose of having sexual relations with her, and she asked him what he would give her.  This would have reinforced the idea that she was a harlot.  Verse seventeen says, And he said, I will send thee a kid from the flock. And she said, Wilt thou give me a pledge, till thou send it?  Judah promised her a kid from his flock, but Tamar asked for a pledge, something of value, to ensure that Judah would carry out his promise.  He had already made a promise to her once before.  Of course, Judah was not acting much like a man who was following God.  As followers of Christ, when we see people acting in a sinful way, we can either attempt to bring people up God, ignore them, or move down to their level ignoring God's guidance.  Verse eighteen adds, And he said, What pledge shall I give thee? And she said, Thy signet, and thy bracelets, and thy staff that is in thine hand. And he gave it her, and came in unto her, and she conceived by him.  Judah asked Tamar what she wanted for a pledge, and she said his signet, bracelets and staff.  Judah had to put a little faith in her returning these things when he sent her the kid.  Verse nineteen declares, And she arose, and went away, and laid by her vail from her, and put on the garments of her widowhood.  After being with Judah, Tamar again put on her garments of widowhood.  We cannot sin and then just go on as if nothing had happened, because no matter if anyone else ever knows or not, God does.  Christianity cannot be like a robe that we put on and take off when it stands between what we want and following God's will.