15 Then from his mouth the serpent spewed water like a river, to overtake the woman and sweep her away with the torrent. 16 But the earth helped the woman by opening its mouth and swallowing the river that the dragon had spewed out of his mouth.
From these verses it's clear that the devil tries everything in his power to destroy the church, represented by the female figure in these verses, (either Israel or Christianity or symbolic of both). This includes trying to kill her infant son, Jesus, whom God took into the safety of heaven.
Bibleref.com's entry on these verses likens the "river" in verse twelve to an invading army intent on destroying Israel, and speculates that the opening of the dragon's mouth may refer to an earthquake or another act of God in which He intervened and protected the Israelites or the Church from harm from Satan.
Many sources on this verse refer to the events of Ezekiel chapter 38 which tells of an army gathered to invade Israel and an enormous earthquake which foils their conquest.
Verses 18-20 of Ezekiel 38 are very specific about the results of the earthquake, which many writers liken to the 'river' mentioned in verse 16 above: "18 This is what will happen in that day: When Gog attacks the land of Israel, my hot anger will be aroused, declares the Sovereign Lord. 19 In my zeal and fiery wrath I declare that at that time there shall be a great earthquake in the land of Israel. 20 The
fish in the sea, the birds in the sky, the beasts of the field, every
creature that moves along the ground, and all the people on the face of
the earth will tremble at my presence. The mountains will be overturned, the cliffs will crumble and every wall will fall to the ground."
More information on the terms "Gog" and "Magog" on wikipedia: link.
A Prayer for Salvation from Christ:
Lord Jesus, I confess my sins and ask for your forgiveness. Please come into my heart as my Lord and Savior. Take complete control of my life and help me to walk in Your footsteps daily by the power of the Holy Spirit. Thank you Lord for saving me and for answering my prayer.
A more detailed step by step process:
https://www.wikihow.com/Accept-Jesus-Into-Your-Life
