The first principle of the gospel is faith in the Lord Jesus Christ. Elder Eyring has taught that faith "is not simply to know God could do something," rather "faith is to know He will." Knowing God will do something will change our behavior.
Consider how knowledge of what God would do changed the behavior of Enos.
As is often the case, Enos felt compelled to apply to gospel to his life because of some sort of realization of his own weaknesses. He wrote, "And my soul hungered; and I kneeled down before my Maker, and I cried unto him in mighty prayer and supplication for mine own soul; and all the day long did I cry unto him; yea, and when the night came I did still raise my voice high that it reached the heavens" (Enos 1:4).
Enos was motivated to pray through the day and night by his knowledge that God not only could, but would forgive him. This is confirmed by two statements, the first by Enos and the second by the Lord.
After being told he was forgiven, Enos, "knew that God could not lie; wherefore, my guilt was swept away."
Then, in response to Enos' inquiry, the Lord confirmed that forgiveness was possible for Enos "because of thy faith in Christ, whom thou has never before heard nor seen... wherefore, go to, thy faith hath made thee whole."
What would have happened if Enos did not believe God would forgive him? He was the grandson of Lehi, a nephew to Nephi and the son of Jacob-- surely he would have known the doctrine that God could do it. What if he'd have wavered in his belief that God would do it? Would he have prayed as long? Would he have obtained forgiveness? Would there even be an experience worth recording?
Thankfully, Enos did know and God forgave Enos. This confirmation of the faith of Enos expanded his faith further, until Enos' faith "began to be unshaken in the Lord." Enos knew without doubt that God would do all that He had promised through scripture that He could. In the vernacular of Stephen Robinson, Enos not only believed in Christ, Enos believed Christ-- he believed Christ was who He said He was and would do all that He said He would do.
Consider a second example of Enos' faith, how knowing God would act changed his behavior and the result brought by Enos' faith.
Wherefore, I knowing that the Lord God was able to preserve our records, I cried unto him continually, for he had said unto me: Whatsoever thing ye shall ask in faith, believing that ye shall receive in the name of Christ, ye shall receive it.
And I had faith, and I did cry unto God that he would preserve the records; and he covenanted with me that he would bring them forth unto the Lamanites in his own due time.
And I, Enos, knew it would be according to the covenant which he had made; wherefore my soul did rest. (Enos 1:15-17)
What do you know God will do in your own life? Certainly He will grant repentance when it is sought diligently. God will keep His promises. God will bless your life for good, leading you on the best path and protecting you from the devil's snares. These and many other blessings are promised to us in the scriptures and through the ordinances and covenants in which we participate.
As Enos, knowing God will do these things should change our behavior. We should walk through each day confident the Lord is guiding us. We have every reason to be optimistic. Of course we should study and pray and repent and change, for the Lord will richly bless us in our efforts to improve and draw near to Him. This changed behavior, based upon the knowledge of what God will do, is true faith.
God is prepared to bless you and I with the things we desire. He will. Let us have the faith to act upon that knowledge, to move forward with trust in Him. As we do so, He will work miracles because of our true faith, just as He did for Enos.