Reference

John 14:8-17

The works Christ did before He died were spectacular in how they revealed God, demonstrated His authority, and identified that He was the point and fulfilment of every word and deed that God had ever done.  However, the works of Christ to save and transform and build His church, a people redeemed by grace received by faith, will surpass those works in their glorification of His Father.  

The previous works were signs - pointing to a greater reality; however, saving people, reconciling them to the Father, making them new, building the church - these are the realities to which those signs pointed to.  His return to the Father, by His death on the cross for sinners, makes this a reality.  In the Father's sight these works are not less miraculous, they are not less glorious, they are not less sweet. 

For this purpose He gives two generous gifts to all who believe: the Holy Spirit and the gift of prayer - calling on God from Christ's position.  These gifts are given so that we can taste the position which He now enjoys - the position for which He offered His life that we might share.