We learn from the story of Abraham [Chapter 6, An'am (The Cattle): verses 75-80] how to shop for the Truth. (That's Truth with the Capital "T" as in the Arabic word Haqq; aka God:
"[Remember] when Ibrahim said to his uncle, Azar, "Do you take idols for gods? Surely I see you and your people in manifest error." Thus We were showing Ibrahim the kingdom of the heavens and the earth so that he might be of (al-muqinin) those who are sure [of their faith]. So when the night outspread over Ibrahim, he saw a star; he said, "This is my Lord." But when the star set [in the morning,] he said," [This cannot be my Lord because it has passed away,] I do not like the transitory [gods]."
[On the next night,] when he saw the moon rising, he said, "This is my Lord." But when the moon set he said, "If my Lord had not guided me, then I shall surely be of (dha'liyn) the people who have gone astray." [In the morning,] when Ibrahim saw the sun rising, he said, "This must be my Lord [because] this is greater [than the star and the moon!]" But when the sun set, he said, "O my people, surely I am free from what you associate [with God.] I have sincerely turned myself to Him who originated the heavens and the earth, and I am not one of the polytheists." http://www.quranexplorer.com/Quran/?Sura=6&FromVerse=75&ToVerse=80&Reciter=Mishari-Rashid&Translation=Eng-Pickthal-Audio&Zoom=5