"For the Son of man is come to seek and to save that which was lost." It is for this reason that Jesus is likened to the good shepherd who sets off in search of the one lost sheep while leaving the other ninety-nine behind. Thus did the Jewish leaders condemn Him, grumbling because He had gone to eat at the table of a sinner. Likewise did the elder brother of the Prodigal Son take offense when his father prepared a lavish feast on the occasion of the homecoming of his long lost son.
Truly is it written that the angels in heaven rejoice more over the one sinner who is saved than the many who have never fallen into the depths of iniquity. Zacchaeus was indeed a sinner: as chief of the publicans (that is, those who collected the taxes for the despised Roman authorities) he was an oppressor of the poor and downtrodden, striving to enrich himself at the expense of those who struggled to barely survive.
So it was that Jesus sought him, picking him out from among the crowd and commanding that he come down from the sycamore tree. The significant fact, however, is that it was Zacchaeus himself who--by his own free will--first climbed that tree, and the reason he did so was because he fervently desired to see Jesus.
On that day salvation came to Zacchaeus' household--not by some arbitrary act of God, but because he sincerely repented, voluntarily promising to give half of his goods to the poor and to restore fourfold whatever he had taken by false accusation.
The fact is, we are all sinners in need of salvation--we are all lost sheep, having wandered far away from the pasture of the good shepherd. The only question is, shall we--like Zacchaeus--choose the path of repentance, or shall we--like the self-righteous Pharisees of old--condemn ourselves to a hell of our own making?