Young children usually learn better with the use of visual aids. That is why one of the well-known learning experiences young children first encounter is "show & tell" where the children bring in an object and tell about it to their class. If you turn the children's attention to the beauty in nature, you can use various visuals to show them the beauty of God in every creation: people, birds, fish, plants, etc. Perhaps a trip to the zoo would be fun and educational for them. Teach the children to be critical thinkers and reach a conclusion rather than just telling them it is so. Show them and explain how wonderful it is that all these various creations have their own self-governing rules, means of communication, function harmoniously from birth, etc. Even the worm and the vulture have an important job. There must be one God that is able to put this all together. If there is more than one God, then each species might have different rules in its own economy because each God would have a different design in mind. However, every part of creation has one signature, One God. Once they can grasp this idea, then using a children's Bible, walk them through the holy Book of Genesis regarding Creation. Here you will also have the opportunity to demonstrate God's love and care by giving extra special attention to the connectedness and relationship between God and humans, so that you can introduce the Holy Trinity and point out how Jesus Christ is God. Illustrate the strong bond between a parent and a child and how that resembles God and us, His children. The cartoon movie "Finding Nemo" is about a son (a cartoon fish) that wanders off and his father who leaves everything and suffers all kinds of harm in order to bring him back. It is interesting that "nimou" in Coptic means water and this character is a fish in water. Therefore, you can use elements, sources, and media to which they are accustomed in their own lives in order to align their focus on seeing God in everything.
