Why does the God of Times of Grace work in the flesh?

God cannot be revealed directly. In the time of Moses, who had seen God except himself? Only he knows whether he has seen it or not. Looking at a sea of fire in the distance, the ark is covered with curtains. Whoever dares to touch it will die. Who dares to go forward? Thousands of years have passed, and people want to see God more and more. The Bible also says that no one has seen God, and people's doubts naturally arise. People's thoughts are constantly improving, and religion is also advancing with the times. It is incredible to reuse fire and the ark of the Covenant, and religion has entered the era of incarnation.