I think perhaps as a very rough analogy, perhaps Christianity came out of the Essene branch of Judaism, in the same way that the Baha'i faith came out of the Shia branch of Islam?
My question would then be, had Jesus never met the Essenes, would His essential message have been the same?
I'd answer that we simply don't know – how can we?
But we can assert that what He preached, especially as understood and preached by John and by Paul, is a whole different world compared to the teachings of the Essenes (as we understand them) as it does any and every other school of Jewish mystical speculation.
For Paul, 'baptism' is not the ritual washing in the
mikvah as done by Jews generally (including the Essenes).
Baptism is a concrete transformation in the person here and now – a participation in the death and resurrection in the Risen Christ.
In Romans 6 Paul speaks of baptism. In the early church, it seems baptism was a complete immersion. The catachumen stripped off their old clothes, and were then clothed with new – possibly a gift of the community, perhaps just a garment worn on that occasion to symbolise the idea of rebirth and, perhaps, transfiguration.
Paul does not interpret the ritual in terms of cleansing (as it was commonly understood). It was that, and more.
“Are you ignorant that whoever has been immersed into Christ Jesus has been immersed into his death?” (6:3). To go under the water is to die with Christ and to be buried with him, while to rise out of the water is to be raised from the dead and to ascend with him to new life.
"For if we have been united with him in a death like his, we shall certainly be united with him in a resurrection like his. We know that our old self was crucified with him so that the sinful body might be destroyed, and we might no longer be enslaved to sin. For he who has died is freed from sin. But if we have died with Christ, we believe that we shall also live with him. For we know that Christ being raised from the dead will never die again; death no longer has dominion over him. The death he died he died to sin, once for all, but the life he lives he lives to God. So you also must consider yourselves dead to sin and alive to God in Christ Jesus." (6:5-11)
Paul is fully aware of the dilemma in the early church with regard to the immanent return of Christ in Glory and, so far, His failure to reappear. He (as does John) preaches that we will be raised into the glorified life of the eschaton—hence the future tense (“we shall also live with him”) – but here and now we share in the power of the resurrection of Christ in his Spirit:
"But you are not in the flesh, you are in the Spirit, if in fact the Spirit of God dwells in you. Any one who does not have the Spirit of Christ does not belong to him. But if Christ is in you, although your bodies are dead because of sin, your spirits are alive because of righteousness. If the Spirit of him who raised Jesus from the dead dwells in you, he who raised Christ Jesus from the dead will give life to your mortal bodies also through his Spirit which dwells in you." (9-11)
“Therefore, if any one is in Christ, he is a new creation; the old has passed away, behold, the new has come” (2 Corinthians 5:17).
This latter speaks of a corporeal resurrection in the eschaton – again something His contemporaries did not preach.