(John 19:17)
At first there was no-one to help Jesus to bear his cross … Yet we must remember that while Jesus had to bear the cross unaided, it really was not for himself that he bore it, but for us … The Baptist said when Jesus passed by him at the beginning of his ministry, “Behold the Lamb of God, which taketh away the sin of the world!” We may say the same words as we see Jesus bearing his cross. That is what he is doing.

IT WAS NOT THE MERE WOOD that was so heavy; the real load which Jesus bore that day was the mountain of our sins. It was this that made him faint and sink down by the way, and that wrung from him such cries and tears in Gethsemane and on Calvary.

A little later he sank down under the burden … then the scene was this – Jesus and Simon of Cyrene together carrying the cross, Jesus in advance carrying the heavy end, and Simon coming behind bearing the lighter end.
(J. R. Miller)