Jesus said to His Ministers: "Keep on going into all the World, making all nations into disciples, baptizing them into the Name of the Father and the Son and the Holy Spirit — teaching them to keep on observing all things whatsoever I have commanded you! And look, I am always with you — even till the end of the World!" — Matthew 28:19 cf. Revelation 7:3f & 14:1-7 & 15:2-4.
Now "making all nations into disciples" means catechizing and baptizing all Christ-professing adults and their children, and then training such always to be faithful to the one true Triune God. Baptism is a badge or helmet to be worn lifelong on the head of every Christian Soldier, from the womb to the tomb. It requires allegiance to, and under the banner of, the King of kings.