What is the meaning of Mark 8:34?

And when he had called the people [unto him] with his disciples also, he said unto them, Whosoever will come after me, let him deny himself, and take up his cross, and follow me. (Mark 8:34 KJV)

And he called unto him the multitude with his disciples, and said unto them, If any man would come after me, let him deny himself, and take up his cross, and follow me. (Mark 8:34 ASV)

And having called the crowd with his disciples, he said to them, Whoever desires to come after me, let him deny himself, and take up his cross and follow me. (Mark 8:34 DBY)

He called the multitude to himself with his disciples, and said to them, “Whoever wants to come after me, let him deny himself, and take up his cross, and follow me. (Mark 8:34 WEB)

And having called near the multitude, with his disciples, he said to them, `Whoever doth will to come after me–let him disown himself, and take up his cross, and follow me; (Mark 8:34 YLT)

Interlinear

And <kai> when he had called <proskaleomai> the people <ochlos> unto him with <sun> his <autos> disciples <mathetes> also, he said <epo> unto them, <autos> Whosoever <hostis> will <thelo> come <erchomai> after <opiso> me, <mou> let him deny <aparneomai> himself, <heautou> and <kai> take up <airo> his <autos> cross, <stauros> and <kai> follow <akoloutheo> me. <moi> (Mark 8:34 KJV)

Philip Doddridge

Then having called the multitude, with his disciples to him, he said unto them all, You must not only expect to see me suffer, but to share with me in my afflictions and sorrows, if ever you would hope to obtain a part in the glories of my kingdom: if any one therefore is willing to come after me, and attend me as a faithful servant and disciple, let him learn to deny himself in the dearest pleasures and interests of this present life, and habituate himself daily to take up his cross: let him submit to whatsoever trial Providence may lay before him, and be ready to follow me, even to crucifixion itself; for till he is taught a readiness to meet death, even in that dreadful form, for my sake, he has attended my other instructions in vain. (Compare Mt 10:38)

John Wesley’s Notes on the Old and New Testaments

Verse 34.  And when he called the people-To hear a truth of the last importance, and one that equally concerned them all.  

Let him deny himself-His own will, in all things small and great, however pleasing, and that continually:  

And take up his cross-Embrace the will of God, however painful, daily, hourly, continually. Thus only can he follow me in holiness to glory.