All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.
Allah Says (what means): {And whoever seeks a religion other than Islam, it will never be accepted of him, and in the Hereafter he will be one of the losers.} [Quran 3:85] Allah also says: {And say, "Ours is] the religion of Allah. And who is better than Allah in [ordaining] religion? And we are worshippers of Him.} [Quran 2:138]
The Christians were used to baptizing their children with water, and called it baptism. Ibn Abbas said: “Christians used to immerse their newborn babies on the seventh day and called it purification in place of circumcision. They believe that a child becomes Christian by this way. Allah has refused this and stated that the best religion is to follow His Commands, that is Islam. Abu Hurayrah narrated that the prophet said: "Every child is born on the Fitrah (human disposition upon which Allah created mankind – i.e. to believe in Him Alone and not associate with Him any partners), then his parents make him/her a Jew, a Christian or a Magi.” [Al-Bukhari and Muslim]
We would like to remind you, dear brother, that what they want to do to your child (Baptism) is the very same thing that Allah has prohibited, and He replaced it by purification, that is Islam. You must prevent them from Christianizing your child. If he grows up and follows them, and this is what they want, then you will be held responsible for his sins, as per the Hadeeth in which the Prophet stated that the parents make their child a Jew or Christian.
May Allah help us to save our offspring from all evil.
Allah Knows best.