Xenophon,
Anabasis 3.1.43 (tr. Robin Waterfield):
And there's something else that I've observed, my friends: in
warfare those who seek to stay alive, no matter what it takes, are
usually those who die cowardly and ignominious deaths, while those
who have realized that death is the common lot of all men, and
therefore strive for noble deaths, are those who, in my experience, are
somehow more likely to reach old age and to enjoy the time they have
while they are alive.
ἐντεθύμημαι δ᾽ ἔγωγε, ὦ ἄνδρες, καὶ τοῦτο, ὅτι ὁπόσοι μὲν μαστεύουσι ζῆν ἐκ παντὸς τρόπου ἐν τοῖς πολεμικοῖς, οὗτοι μὲν κακῶς τε καὶ αἰσχρῶς ὡς ἐπὶ τὸ πολὺ ἀποθνῄσκουσιν, ὁπόσοι δὲ τὸν μὲν θάνατον ἐγνώκασι πᾶσι κοινὸν εἶναι καὶ ἀναγκαῖον ἀνθρώποις, περὶ δὲ τοῦ καλῶς ἀποθνῄσκειν ἀγωνίζονται, τούτους ὁρῶ μᾶλλόν πως εἰς τὸ γῆρας ἀφικνουμένους καὶ ἕως ἂν ζῶσιν εὐδαιμονέστερον διάγοντας.
Matthew 16:25 (KJV):
For whosoever will save his life shall lose it: and whosoever will lose his life for my sake shall find it.
ὃς γὰρ ἐὰν θέλῃ τὴν ψυχὴν αὐτοῦ σῶσαι ἀπολέσει αὐτήν· ὃς δ’ ἂν ἀπολέσῃ τὴν ψυχὴν αὐτοῦ ἕνεκεν ἐμοῦ εὑρήσει αὐτήν.