Alma contrasts the darkness and tribulation with the everlasting burning after his redemption. Note that he very clearly (verse 28) creates the contrast between being “nigh unto death” and “I am born of God.”
The symbolism of the situation is abundantly clear to Alma immediately after the experience. Alma has been born of God, and is now a “son” of the Savior (Mosiah 5:7 And now, because of the covenant which ye have made ye shall be called the children of Christ, his sons, and his daughters; for behold, this day he hath spiritually begotten you; for ye say that your hearts are changed through faith on his name; therefore, ye are born of him and have become his sons and his daughters.)