"...Do ye not suppose that I know of these things myself? Behold, I testify unto you that I do know that these things whereof I have spoken are true. And how do ye suppose that I know of their surety?
Behold, I say unto you they are made known unto me by the Holy Spirit of God. Behold, I have fasted and prayed many days that I might know these things of myself. And now I do know of myself that they are true; for the Lord God hath made them manifest unto me by his Holy Spirit; and this is the spirit of revelation which is in me."
I underlined several things that stood out to me, one of them being the question, how do we know if our prayers are being answered. Alma gives the answer in the next verse saying that it is through the Holy Ghost, fasting, praying, and the spirit of revelation.
He then goes on to say that it has been revealed to him that the words that their fathers had spoken were true according to the spirit of prophecy as well as by the Spirit of God or Holy Ghost. After that he concludes by bearing his powerful testimony of Jesus Christ and His Atonement:
"I say unto you, that I know of myself that whatsoever I shall say unto you, concerning that which is to come, is true; and I say unto you, that I know that Jesus Christ shall come, yea, the Son, the Only Begotten of the Father, full of grace, and mercy, and truth. And behold, it is he that cometh to take away the sins of the world, yea, the sins of every man who steadfastly believeth on his name."
I know that these scriptures are true and I know that we can all know they are true by praying about them. Receiving answers to our prayers takes effort and the Lord recognizes and blesses our efforts. I know that prayers are answered, because mine have been. I testify of these things in the name of Jesus Christ, amen.