Mar 4:11  And he said unto them, Unto you it is given to know the mystery of the kingdom of God: but unto them that are without, all these things are done in parables: 

Rom 11:25  For I would not, brethren, that ye should be ignorant of this mystery, lest ye should be wise in your own conceits; that blindness in part is happened to Israel, until the fulness of the Gentiles be come in. 

Rom 16:25  Now to him that is of power to stablish you according to my gospel, and the preaching of Jesus Christ, according to the revelation of the mystery, which was kept secret since the world began, 

Eph 1:9  Having made known unto us the mystery of his will, according to his good pleasure which he hath purposed in himself: 

Eph 3:3  How that by revelation he made known unto me the mystery; (as I wrote afore in few words,
Eph 3:4  Whereby, when ye read, ye may understand my knowledge in the mystery of Christ)
Eph 6:19  And for me, that utterance may be given unto me, that I may open my mouth boldly, to make known the mystery of the gospel,
Col 1:26  Even the mystery which hath been hid from ages and from generations, but now is made manifest to his saints:
Col 1:27  To whom God would make known what is the riches of the glory of this mystery among the Gentiles; which is Christ in you, the hope of glory:

2Pe 3:9  The Lord is not slack concerning his promise, as some men count slackness; but is longsuffering to us-ward, not willing that any should perish, but that all should come to repentance.

God's will is simply this; that all men should turn to Him and be reconciled!