Matthew 16:26

“For what will a man be profited, if he shall gain the whole world, and forfeit his life? Or what shall a man give in exchange for his life?” '

So He puts to those who were following Him (and to us) the ultimate challenge. Of what advantage is there for anyone to gain the whole world and as a result forfeit eternal life? And if he failed to follow Christ what could a man possibly offer to God in exchange for his life? Jesus knew the temptation. He had been offered the whole world by Satan (Matthew 4:8). But He had turned it down. In a lesser way men have stood astride their world many times in history, and have received much glory and wealth, but in the end all have died, and perished. Not one is alive today. And thus ultimately, if their living had not been for Christ, they had lost all. They may be famous names in the history books, but if their names were not written in Heaven, they have nothing. Are they, asks Jesus, the gainers or the losers? But to the one who comes to Him, yielding himself to Him, He gives eternal life. By giving up what they cannot finally keep, they gain what they cannot lose. In return, however, they must be ready to lay their lives on the line for Him, and to follow Him utterly. This is a constant theme in the New Testament (John 3:17; Joh 3:19; 1 Corinthians 1:18; 2 Corinthians 4:18; Gal 2:20; 2 Peter 1:4; 1 John 2:15). It is not that by this they buy themselves life. It is because they cannot find life apart from following the One Who will give His life a ransom for many (Matthew 20:28).

Some have seen this verse as partly based on Psalms 49. ‘Those who trust in their wealth, and boast themselves in the huge amount of their riches, none of them can by any means redeem his brother, nor give to God a ransom for him -- that he should still live always, that he should not see corruption -- but God will redeem my soul from the power of Sheol, for He will receive me. Do not be afraid when one is made rich, when the glory of his house is increased, for when he dies he will carry nothing away' (Psalms 49:6; Psalms 49:15). In that Psalm it was clearly indicated that there was no way by which men could redeem themselves, however rich they were. There was nothing that they could give in exchange for true life. Only God could redeem them.