When we become anxious, we seek something tangible and concrete to comfort us. For little children, it could be a stuffed animal, which helps them to sleep, such as the tiger Hobbes was for Calvin. We are people geared to see, to touch, to feel. We are experts in the concrete world of the senses.
But when it comes to the less observable parts of life, such as love or affection from another, we cannot always be completely reassured by tangible signs. There comes a time when we simply must trust. This is true whether we are discussing another person or with God.
To deal with this temptation, it is the reason that images were not carved in representing God. And on the surface, it is why the people fashion a Golden Calf. They believe on some level that this is the way to strengthen their faith. But it is the lack of faith this action represents. Moses is delayed, the clouds are scary, and the mountain is far. When will Moses come back? Is he even still alive?
If we are looking for dependable signs, it is in seeking to place ourselves into situations where we would be able to experience God. We seek out others, even though they too require trust, because people are made in the image and likeness of God.
We see time and again that the Israelites have trouble trusting God. So too do we. Let us pray for an increase of faith in God.