“Whatever principle of intelligence we attain unto in this life, it will rise with us in the resurrection. And if a person gains more knowledge and intelligence in this life through his diligence and obedience than another, he will have so much the advantage in the world to come.” D&C 130:18-19
“Knowledge and intelligence” are two interesting choice of words from the prophet. Most people today would conflate those words to mean how much information and brainpower has been acquired; but it is far more. “Knowledge” is a reference to our relationship with the Lord. That relationship will determine the level of “intelligence” that we receive.
The level of intelligence we obtain is the same as how much light and glory we are given. This is how “grace” is received from God. Not by our own power, but by God’s mercy; thereby, we are given opportunities in life to receive more knowledge and intelligence. All these mercies are made available to those who make covenants with the Lord; either before they are born or hereafter.
In these links I will lay out a portion of the Plan of Salvation in a way to help you see the broader picture of mortality. This is a part of the Everlasting Covenant, but I will only go as far as what is needed during this life for those who will be the Servants of the Lord.