Raising of Lazarus Duccio.jpgBefore Your own death, O Christ, You raised from death
Lazarus, who was four days dead, and You have shaken the dominion of death. Through
the one man whom You loved, You have foretold the deliverance of all from
corruption. We therefore worship You and cry: Blessed are You, O Savior! 
Have mercy on us!

The observance of Lazarus Saturday is really more a Byzantine Church observance on the Saturday before Palm Sunday, but you will find it in the West, too. As the antiphon above notes, Jesus shows us what is come for us who believe in Him: triumph over death by death itself. As Jesus approaches His own death on the Cross, and then the Resurrection, we who believe in the Lord encounter the same fact.