The purpose of God can be viewed through the prism of 1st Corinthians 1:21: “For since in the wisdom of God the world through its wisdom did not come to know God, God was well-pleased through the foolishness of the message preached to save those who believe.”
So that seems to indicate God’s purposes. God purposed to have a Gospel, and that His Gospel was not to unconditionally accept unbelievers, but to offer salvation, with an offer sent out indiscriminately to all men (as per the parable of the Wedding Feast), which was for the purpose that His Father’s House may be “filled,” and that God’s purpose to “save those who believe” in Him will not be thwarted. So if God determines to give eternal life to those who believe in His Son, He will do it.
Luke 14:23: “And the master said to the slave, ‘Go out into the highways and along the hedges, and compel them to come in, so that my house may be filled.’”
God’s desire is that all men come to know Him, and His stated purpose in the Gospel is that whosoever does believe in Him, He will fulfill His promise to give eternal life.