This verse is full of very important symbols. First of all, water is the primordial element from which the life emerged. In the Bible, water is chaos, something unfathomable and scary that you would like to avoid. It also represents anxiety, an obstacle to overcome to enter into a full and happy life. Jesus, coming out of the water, dates from life to death, but also from anguish. In this case it is simply a ritual passage, which then finds substance in the episode of the Getsemani Garden, where instead he will have to face it pointing at all the way to overcome it. However, before coming out of the water, Jesus had immersed himself – baptizein means to dive – not refusing this so human passage, but also so divine. Among other things, the evangelist Matthew does not say a word about the act of Baptism, that of dripping in the waters. This would mean that Matthew is particularly interested in what comes after Baptism.
Beyond the sea you reach the shore of a new life where the sky is not closed. God begins to communicate with man who is no longer afraid, who does not fear God, because he believes that from God come only good things. The dove is a symbolic being that represents heaven and all that comes from heaven, like the Spirit over Jesus, making him suitable to begin his mission. This is a very personal experience, because only Jesus sees and experiences these things. Some scholars maintain that the Baptism is similar to the practice of shamanic initiation, where the spirit makes the shaman able to carry out his task within the clan. So the shaman can heals others because he has healed himself, as Jesus will do. However, these and other parallels are not entirely satisfactory in the case of Jesus, because his figure brings together many elements, common to many ancient religions. But his figure is unique with regard to all the others religious leaders.
In fact, in the case of Jesus, the Gospels do not speak of ecstatic or euphoric states as happens during the shamanic initiation, but only of the spirit that from then on permanently resides upon him, allowing him to carry out the mission that the Father he had entrusted him. The heavens that open are a symbolic expression to say that after baptism, after diving and emerging from the death of anguish, God begins to speak to man who only then becomes his Son, that is, a human being who has a full and vital relationship with Him.