Here is what Bruce R McConkie had to say about being valiant.
Bruce R. McConkie, “Be Valiant in the Fight of Faith,” Ensign, Nov 1974, 33
Now what does it mean to be valiant in the testimony of Jesus?
It is to be courageous and bold; to use all our strength, energy, and ability in the warfare with the world; to fight the good fight of faith. “Be strong and of a good courage,” the Lord commanded Joshua, and then specified that this strength and courage consisted of meditating upon and observing to do all that is written in the law of the Lord. (See Josh. 1:6–9.) The great cornerstone of valiance in the cause of righteousness is obedience to the whole law of the whole gospel.
To be valiant in the testimony of Jesus is to “come unto Christ, and be perfected in him”; it is to deny ourselves “of all ungodliness,” and “love God” with all our “might, mind and strength.” (Moro. 10:32.)
To be valiant in the testimony of Jesus is to believe in Christ and his gospel with unshakable conviction. It is to know of the verity and divinity of the Lord’s work on earth.
But this is not all. It is more than believing and knowing. We must be doers of the word and not hearers only. It is more than lip service; it is not simply confessing with the mouth the divine Sonship of the Savior. It is obedience and conformity and personal righteousness. “Not every one that saith unto me, Lord, Lord, shall enter into the kingdom of heaven; but he that doeth the will of my Father which is in heaven.” (Matt. 7:21.)
To be valiant in the testimony of Jesus is to “press forward with a steadfastness in Christ, having a perfect brightness of hope, and a love of God and of all men.” It is to “endure to the end.” (2 Ne. 31:20.) It is to live our religion, to practice what we preach, to keep the commandments. It is the manifestation of “pure religion” in the lives of men; it is visiting “the fatherless and widows in their affliction” and keeping ourselves “unspotted from the world.” (James 1:27.)
To be valiant in the testimony of Jesus is to bridle our passions, control our appetites, and rise above carnal and evil things. It is to overcome the world as did he who is our prototype and who himself was the most valiant of all our Father’s children. It is to be morally clean, to pay our tithes and offerings, to honor the Sabbath day, to pray with full purpose of heart, to lay our all upon the altar if called upon to do so.
To be valiant in the testimony of Jesus is to take the Lord’s side on every issue. It is to vote as he would vote. It is to think what he thinks, to believe what he believes, to say what he would say and do what he would do in the same situation. It is to have the mind of Christ and be one with him as he is one with his Father.