Well the one true God has revealed Himself in the Holy Scriptures that He led His servants to write many centuries ago Kendra. Unfortunately I cannot remember where it comes from but I know God says somewhere in the Old Testament. "I am the Lord alone. Apart from me there is no other God."
The book of Judges is full of incidents in Israel's history when they abandoned God to worship the idols of all the gentile nations and God proved time and time again that these gods had no power at all to protect them by delivering them into the hands of invaders until they cried out to Him for mercy and He sent judges to fight their enemies and deliver them. But after each judge died they kept repeating their folly. Elsewhere it says that all the gods of the nations are only blocks of wood, stone, gold, silver etc. Whatever they're made of, idols stand for things that don't really exist, but the invisible all-powerful God created all things.