What it means is that the giving of agape love (look up agape in the dictionary), is followed by a outpouring of spiritual thought and actions.
I am not certain it is true for Satanists.
What the heck does "The law of divine love is the cause of one’s spiritual life" mean in simple English?
2 answers
The "law of divine love" as I understand it is "to love one another as I (God) have loved you". ...in brief to love ones fellow human beings. That is the purpose of how one lives in the "spirit" of God. Others may see this quote in a different way.