Well building a testimony is an eternal process. For our earthly life we are going to be going by faith. For after the resurrection we will not be acting by faith after we see our Savior Jesus Christ. We will have a perfect knowledge. But first we need to know the basics. What is a testimony? How do we build a testimony?
Elder Robert D. Hales, Quorum of the Twelve Apostles
You can gain your testimony the same way the prophets gained theirs—through the witness of the Spirit.
"Our testimony comes by the gift and power of the Holy Ghost. The testimony received and carried within us enables us to hold a steady course in times of prosperity and to overcome doubt and fear in times of adversity. Each of us needs to know what a testimony is, how we can get it, and what our responsibilities are once we have received a testimony.
A testimony is the spirit of prophecy (see Rev. 19:10). It is a personal revelation from God, revealing the truthfulness of the gospel of Jesus Christ. A testimony comes through the Holy Ghost; it makes a deep and lasting impression on the soul. Individual testimonies are the foundation and strength of the Church. Our testimony provides a guiding light that leads to a commitment which directs our conduct and our way of life. Our testimony is true north on a spiritual compass. It is a moving force that cannot be seen but can truly be felt. It is a burning within that tells us what is right. It is when, as President Harold B. Lee (1899–1973) said, “your heart tells you things your mind doesn’t know” (Speeches of the Year, 1973, 101).
Our testimony is the fruit of obedience in the form of peace, joy, and understanding in our hearts of gospel principles. A testimony is a shield of faith “wherewith ye shall be able to quench all the fiery darts of the wicked” (D&C 27:17). Our testimony is a measurement of our faith. Faith is testimony; testimony is faith. Having a strong testimony allows us to help others in their search for truth. Our testimony is a gift from God. It should be shared, but we do not have the authority to bestow a testimony upon someone else, because a personal testimony is granted by the Holy Ghost. It can aid others in gaining knowledge for themselves—a knowledge abiding in the heart that leaves no room for doubt.
Our testimony is a knowledge of who we are, where we came from, and where we are going eternally if we are faithful. We must each gain such a testimony if we are to withstand the trials and adversities of mortality and go on to the glorious eternal future we all desire.
What do we learn about testimony from the lives and teachings of the prophets of God? We learn that a testimony is very personal. We can each gain a testimony of the truth through the Holy Ghost.
People often ask me, “How do you know? How can you know that God lives and that Jesus is the Christ?” While there seems to be no exact formula by which each of us receives a testimony, there does seem to be a discernable pattern. Though prayer is important in gaining a testimony, we cannot merely ask in prayer for a testimony and expect it to be given immediately to us.
Generally, testimony emerges over time and through life’s experiences. We can compare testimony to the process of watching a photograph develop. Powerful impressions of the Spirit come like flashes of light on receptive photographic film. Like the chemicals needed to develop the picture, certain spiritual conditions and experiences are needed in our lives for our personal testimony to develop into a certain truth and knowledge. And like a photograph, a testimony, if not carefully preserved, will fade with time.
Testimonies often come when there is willingness to serve where we are called. They come when a decision is made to strive to be obedient. Testimonies come during efforts to help, lift, and strengthen others. They come from prayer and from studying the scriptures and applying them in our lives. Whatever our circumstances, there seem to be moments in each of our lives when we can be given the knowledge that God lives and that Jesus is the Christ. There is no greater search in life that we can embark upon than the quest to gain a testimony of the truth.
While each of our lives is different, I believe we can, with some confidence, outline from the testimony of others, such as the prophets, and our personal experience the process and phases we go through to gain a testimony:
Continue to pray. Have a sincere desire to know the truth and express that desire in humble prayer to our Heavenly Father. “If ye can no more than desire to believe, let this desire work in you” (Alma 32:27). Search the scriptures. The scriptures are filled with the testimonies of those who have gone before. Even they, though long dead, can reach our heart and bring peace to our minds and direction to our lives.
Ponder gospel principles. Think about them. Test them with further prayer. Relate them to what we know and feel. All the truths we will learn can eventually fit together into a fervent, undoubting testimony.
Be humble and receptive. Have ears to hear when Heavenly Father leads us to someone who can teach us about the gospel of Jesus Christ. This may be a teacher, family member, neighbor, friend, or acquaintance. It might be a missionary who contacts us through tracting or referral. But know that once we pray, study, and have faith with a desire to learn spiritual matters, the Lord will provide a way for us to gain further light and knowledge.
Live our testimony. We must obediently follow the Savior’s teachings and the prophets’ examples. Our testimony and example will assist others who are searching for the truth.
Share our testimony. “O that I were an angel,” proclaimed Alma, “and could have the wish of mine heart, that I might go forth and speak with the trump of God” (Alma 29:1). Let others know that we know. Bear our testimony in fast meeting. Tell our family; tell our friends. We will find when we share our testimony it becomes stronger, and there are many others around us who also want to embrace the truth. Be willing to endure the test of time. Do not think that it is easy to maintain a testimony. Others will test us. Sometimes they will point the finger of mockery and scorn. Sometimes they may persecute you openly. Be prepared. Know in advance that the best of God’s children have had the courage of true conviction and were willing to suffer ridicule, deprivation, and even death for the sake of true testimony. Is each of us willing to do likewise?
We also know that if we do not continue faithful in the testimony that is imparted to us by the Spirit, then the light dwindles until it is extinguished. A testimony must be constantly nourished and defended, or it will waste away.
I wish to bear my own testimony in the strongest and most direct manner possible. I know that God lives. I bear witness to the reality and divinity of His Son Jesus Christ, who leads this Church, and who reveals the word of the Father to our generation. I bear my testimony to the gift and power of the Holy Ghost, the eternal nature of the priesthood, the calling of the Prophet Joseph Smith, the Book of Mormon, and the assurance that God has again spoken through a living prophet." (New Era, August 2002)
Here you have just read a testimony from a modern day prophet, seer and revelator. Take this testimony and let it work in you until you have your own. Rely on his testimony until you have your own.
The ancient record or the Gold Plates were preserved from generation to generation until the Prophet Moroni sealed them up until the day that they were to be brought forth. The Angel Moroni appeared to the Prophet Joseph Smith and directed him to these ancient records which were buried in a hill called Cumorah. Joseph Smith translated the record from ancient text that nobody on earth knew to english by the Power of God. The only way that this could have been was by the power of God. 
