Zacchaeus was a rich and dishonest tax collector. He was visited by Christ and the encounter caused a radical change. Zaccheus experienced the mercy and forgiveness of Christ.
God calls us to enter into communion with Him. The call is for everybody to witness His glory and to humble ourselves before Him. We are invited to walk towards God, to clean our hearts as we fix our eyes on Him. To respond to the call requires an awareness of our sins, defects and weaknesses, such that we meet God when He grants His mercy for us sinners.
Conversion brings about in us an experience similar to Zacchaeus, from a repentant attitude, to a change in heart, and a change in how we conduct ourselves with others. Salvation comes to our house when we welcome Jesus Christ.