A toddler living by a busy street will be told never to cross it. She will be told that it is dangerous and that a car could run over her. At 3 years old, she can understand this.
When the girl gets a little older, she may want to visit her friend who lives across the street. It is still dangerous to cross the street. The girl is small and drivers may not see her. At 5 years old, she can understand the need of an adult holding her hand to cross.
Eventually, the girl gets old enough to visit her friend by herself. Her mom reminds the girl to look both ways and only cross when it is safe to do so. At ten years old, the girl can understand these instructions and follow them with exactness.
Later, the girl will become a women. She will have her own girl, whom she will tell never to cross the street.
Did the rule change? Crossing the street was always dangerous, and remains so, even though the girl is old enough to cross it alone. The rule did not change. The girl's capacity to understand the rule changed.
Likewise, God's rules never change. His instructions might change, with our capacity to understand.
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