Ezra 9:2 King James Version (KJV)
2 For they have taken of their daughters for themselves, and for their sons: so that the holy seed have mingled themselves with the people of those lands: yea, the hand of the princes and rulers hath been chief in this trespass.

Who is it that shows the aggressive evil spirit, that the Lord should proclaim this? the men who peacefully seek to increase and multiply or the sons of God? The sons of God, certainly. Then it follows that the strength of the text applies to them, and that the Spirit shall not always strive with them, for they also are flesh; and if flesh, then they are men also. If they also are men, why should they be separately classed from the sons of Adam? It is because they are of another race, the fruit of another creation of men, even as expressed by the figure of the river of Eden and its four branches. What are their characteristics? the text stated, "There were giants in the earth in those days; and also after that, when the sons of God came in unto the daughters of men, and they bare children to them, the same became mighty men which were of old, men of renown."