Spiritual Children - God's

Now you in reality have acquired all these spiritual children free and gratis [by teaching children’s classes], and that is better than having physical children; for such children are not grateful to their fathers, since they feel that the father serveth them because he must -- and therefore no matter what he doeth for them, they pay it no mind. Spiritual children, however, are always appreciative of their father's loving kindness.

‘Abdu’l-Bahá, The Compilation of Compilations vol. I, p. 273-274

The spiritual father is greater than the physical one, for the latter bestoweth but this world's life, whereas the former endoweth his child with life everlasting.

‘Abdu’l-Bahá, The Compilation of Compilations vol. I, p. 273-274

You are all my children, my spiritual children. Spiritual children are dearer than physical children, for it is possible for physical children to turn away from the Spirit of God, but you are spiritual children and, therefore, you are most beloved.

‘Abdu’l-Bahá, The Promulgation of Universal Peace, p. 92

You who are His spiritual children must by your deeds exemplify His virtues, and witness to His glory.

Shoghi Effendi, The Dawn-Breakers, p. 92