God's purpose in creation was to let us prove ourselves. The plan was explained to us in the spirit world before we were born. We were valiant enough there to qualify for the opportunity to choose against temptation here to prepare for eternal life, the greatest of all the gifts of God.
The Holy Ghost has as a major purpose witnessing that Jesus is the Christ. As we plead for help in His service, the Holy Ghost will come and confirm our faith in Him. Our faith in the Savior will increase. And, as we continue to serve Him, we will come to love Him.
