18. Moreover, if in all them that believed there was, as it is written, one soul and one heart: Acts iv. 32. if every one that cleaveth to the Lord is one spirit, 1 Cor. vi. 17. as the Apostle hath said: if a man and his wife are one flesh: Gen. ii. 24; S. Matt. x. 8. if all we mortal men are, so far as regards our general nature, of one substance: if this is what the Scripture saith of created men, that, being many, they are one, Acts xvii. 26; Gal. iii. 28. who can in no way be compared to Divine Persons, how much more are the Father and the Son one in Divinity, with Whom there is no difference either of substance or of will!