Two disciples leaving Jerusalem start discussing the events of the last few days. As they are walking, a stranger joins them and is told about the what has most recently happened that the men have heard about the empty tomb and the rumours about Jesus being alive. They cannot make sense of these reports, and are surprised when the stranger directs them to thinking about the message of the prophets relating to the fate of the Messiah. When they stop for the night they invite the stranger to join them, and say grace at their meal together. Only then do they realise it is Jesus with them, and before they can respond he's gone again. It leaves them astonished, yet full of encouragement and hope, so they return to Jerusalem that same night, despite travel risks to tell other disciples what happened.
It's yet another story of how the risen Lord is made known when his followers begin to talk about him, try to work out what has happened and what it all means. Thinking about the meaning of scripture in relation to Jesus, remembering him and breaking bread together, are all bound together here, and in this the seeds are sown for all acts of Christian worship and fellowship that will evolve as time passes. There is no elaborate ritual prescription as with Passover and Temple worship under the Jewish Torah.
Speaking to the Samaritan woman at the well, Jesus says;
"The hour is coming, and is now here, when the true worshippers will worship the Father in spirit and truth, for the Father seeks such as these to worship him." (John 4:23)
In his teaching about God's kingdom, he explains his own position;
"Do not think that I have come to abolish the Law or the Prophets; I have not come to abolish them but to fulfill them." (Matthew 5:17)
The fulfilment of all kinds of ritual words and actions prescribed for worship is found 'in spirit and in truth' - the inward disposition of the heart, the sense of purpose and purity of intention towards God that flows from genuine spiritual freedom. It doesn't matter in the end what outward forms worship may take, what matters is the free openness of the heart to give God due honour and praise. The source of this motivation is sharing the story of Jesus, remembering him and what it all means for us and for the world, embedding this in everyday life following him.
The prescriptions of religious tradition aren't abolished, nor are they irrelevant. They are simply no longer binding or restricting, but a foundation that secures the culture of religious worship in its history, with full permission to develop differently in the future. Although the diversity of forms of Christian worship seems very different from those of Judaism, it is not difficult to identify many elements in common - use of Psalms of praise and penitence, the blessing (=giving thanks for) and sharing food (especially bread and wine) and many other gifts of God, public scripture reading, prayer of intercession.
Doing these things together provide a frame of reference, a context in which the risen Jesus continues to reveal his presence to those who continue to commit themselves to worshipping 'in spirit and in truth'.