Ether 12:41

"And now, I would commend you to seek this Jesus of whom the prophets and apostles have written, that the grace of God the Father, and also the Lord Jesus Christ, and the Holy Ghost, which beareth record of them, may be and abide in you forever. Amen."

Moroni, realizing that his time in running out, asks readers to seek Jesus.  Moroni knows the true source of happiness and he wants everyone to find it. By following Christ, we can have God's grace with us.