How many times in the Bible does God refer to Christians as Children?

and they can no longer die; for they are like the angels. They are God's children, since they are children of the resurrection.

Luke 20:35-37 (in Context) Luke 20 (Whole Chapter)

The Spirit himself testifies with our spirit that we are God's children.

Romans 8:15-17 (in Context) Romans 8 (Whole Chapter)

In other Words, it is not the natural children who are God's children, but it is the children of the promise who are regarded as Abraham's offspring.