I) [Mt 16:24-27]:
(v. 24) "Then Jesus said to His disciples, 'If anyone would come after Me, he must deny himself and take up his cross and follow Me.
[Notice that "coming after Me [Jesus]", i.e., discipleship and not salvation is in view, i.e., following the Lord in service, denying one's own personal direction and accepting the Lord's direction in one's life to the extent of taking up one's particular cross in life of difficulty, persecution and service to God]
(v. 25) For whoever wants to save his life will lose it, but whoever loses his life for Me will find it.
[So in light of the previous verse the phrase
"to save his life" = "ton ...psuchen autou .sosai" =
.................................."the... life .......,your...to save" =
to preserve his life, his physical life and the value of it as the rest of the passage indicates to earn a reward when Christ comes again.
Notice that since salvation unto eternal life is not a reward but a gift, (Eph 2:8-9, Ro 3:23-24), then something other than eternal life is in view in this passage.
"but whoever loses his life for Me will find it" = Notice that Eternal Life vs the Lake of Fire cannot be in view here because losing one's life for Christ results in finding it. What is in view is finding one's life, i.e., preserving the value of one's life via service to the Lord = becoming a disciple]
(v. 26) What good will it be for a man if he gains the whole world, yet forfeits his soul?
[So gaining the whole world is pictured as valueless in some respect: the eternal respect; for worldly gains are only shortlived, temporal. But the value of one's life which is found in serving Christ results in eternal rewards that will last forever]:
(v. 27) For the Son of Man is going to come in His Father's glory with His angels, and then He will reward each person according to what he has done."
[Notice that the one who loses, i.e., gives up control of his life by committing it to serving the Lord will preserve his life, i.e., preserve its value in eternity for rewards when the Lord comes again.
Detailed study on gaining/losing the soul in the bible ]
II) [Mt 16:28, cf. Lk 9:27-35; Mk 9:1-9]:
"I [Jesus, (v. 24) tell you [the disciples, (v. 24)] the truth, some who are standing here will not taste death before they see the Son of Man coming in His kingdom."
"some who are standing here will not taste death" = This phrase limits the fulfillment of this prophecy to the disciples' physical lifetimes.
"before they see the Son of Man coming in His Kingdom" =
"coming" = "erchomenon" = present participle which indicates that our Lord must be seen in a present condition of coming in His Kingdom.
So "some" of the disciples in their physical lifetimes, (Peter, James and John), must see our Lord in His glory as He comes to bring in His Kingdom. And this is precisely what happens at the transfiguration account in Mt 17:1-9 quoted below which refers to Jesus as the Son of Man and shows a picture of Him and how he will appear as He is coming to bring in His Kingdom. This account immediately follows the prophecy in Mt 16:28 in time and in Scripture:
(v. 1) "After six days Jesus took with Him Peter, James and John the brother of James, and led them up a high mountain by themselves.
(v. 2) There He was transfigured before them. His face shone like the sun, and his clothes became as white as the light.
(v. 3) Just then there appeared before them Moses and Elijah, talking with Jesus.
(v. 4) Peter said to Jesus, 'Lord, it is good for us to be here. If you wish, I will put up three shelters - one for You, one for Moses and one for Elijah.'
(v. 5) While he was still speaking, a bright cloud enveloped them, and a voice from the cloud said, 'This is my Son, Whom I love; with Him I am well pleased. Listen to Him!'
(v. 6) When the disciples heard this, they fell facedown to the ground, terrified.
(v. 7) But Jesus came and touched them. 'Get up,' He said. 'Don't be afraid.'
(v. 8) When they looked up, they saw no one except Jesus.
(v. 9) As they were coming down the mountain, Jesus instructed them, 'Don't tell anyone what you have seen, until the Son of Man has been raised from the dead.' "
[C.I. Scofield states in footnote #2 in the Oxford NIV Scofield Study Bible, NIV, C. I. Scofield, Editor, Oxford University Press, 1984, p. 998]:
"The transfiguration scene contains, in miniature, all the elements of the future kingdom in manifestation (2 Pet 1:15-21):
(1) the Lord Jesus, not in humiliation but in glory (v. 2);
(2) Moses, in glory, representative of the redeemed who have passed through death into the kingdom (Mt. 13:43; cp. Lk 9:30-31);
(3) Elijah, in glory, representative of the redeemed who have entered the kingdom
(4) Peter, James, and John, not glorified, representatives, for the moment, of Israel in the flesh in the future kingdom (Ezek 37:21-27);
(5) the crowd at the foot of the mountain (v. 14), representative of those who are to be brought into the kingdom after it is established over Israel (Isa 11:10-12; etc.).
2 Peter 1:16-18 verifies the fulfillment of Mt 16:28 in the events portrayed in Mt 17:1-9:
[2 Peter 1:16-18]:
(v. 16) "We did not follow cleverly invented stories when we told you about the power and coming of our Lord Jesus Christ, but we were eyewitnesses of His majesty.
(v. 17) For He received honor and glory from God the Father when the voice came to Him from the Majestic Glory, saying, 'This is my Son, Whom I love; with Him I am well pleased.'
(v. 18) We ourselves heard this voice that came from heaven when we were with Him on the sacred mountain."