There are three things that spread the Christ-life to us: baptism, belief, and that mysterious action which different Christians call by different names—Holy Communion, the Mass, the Lord’s Supper. At least, those are the three ordinary methods.C.S.Lewis
What makes the creator of the universe choose these things by which new life is transmited to us?
Take Baptism – there are all the types of it in the Old Testament, the Red Sea and Jordan River crossings. Baptism itself is a type of death and ressurection. How does this transmit a new life?
Or Communion? Eating some bread and drinking some wine typologically portrayed by Melchizedek, and pointing to a torturous murder! The death of Jesus Christ on the cross.
Belief – in a set of precepts? No – in the person Jesus Christ and the effectivenes of His death on the cross to bring us back into relationship with God.