Here are my notes on the topic:
Dedication
The word “dedication” is never used in the scriptures related to baptism. The first mention of any baptism is in Matthew 3:6, so this was not a practice common to the Israelites until a much later period. The only time the word dedication is used in the Greek scriptures is at John 10:22 in relation to the “Festival of Dedication”. The word “dedicated” is used three times in the Greek scriptures, at Matthew 15:5, Mark 7:11 and Luke 21:5. Both Matthew and Mark were discussing corban, a gift dedicated to God, while Luke was discussing how the temple was “adorned with fine stones and dedicated things”. None of these were associated in any way with baptism.
That leaves me to wonder, then why does the Society feel we must first dedicate ourselves to God as a prerequisite to baptism? The scriptures make no such statement. This is yet another example of going “beyond the things that are written.”
Something to note are these two comments from decades ago:
w70 7/1 p. 404 par. 13
Christians must appreciate these facts. Their dedication is not to an organization nor to a work. Neither is it to a human or a government; it is only to the Creator himself, to Jehovah God, through Jesus Christ.
w66 10/1 pp. 603-604 par. 15
We do not dedicate ourselves to a religion, nor to a man, nor to an organization. No, we dedicate ourselves to the Supreme Sovereign of the Universe, our Creator, Jehovah God himself.
The use of “dedication” apparently comes from Jesus’ statement at Matt 16:24: “Then Jesus said to his disciples: “If anyone wants to come after me, let him disown himself and pick up his torture stake and keep following me.”
Something of note, here: “If anyone wants to come after me” and “keep following me”. This is important because dedication to JWs is to Jehovah not to Christ.