The Bible contains many “rules and regulations” concerning baptism. All of these “rules and regulations” in the Bible regarding baptism are for adults since that in the entire Bible the people that are speaking and interacting are an adult, or they are people that are old enough to have a comprehension level of an adult. To better rephrase the latter part of the last statement; all of the Biblical figures, which are adults, are of the age of reason; they are able to discern what is right and what is wrong.
Not only are these people old enough to have an adult comprehension level and be of the age of reason, but also they are old enough to have been able to sin against God several times throughout their lives.
Since they are of the age of reason they are somewhat able to at least recognize that they have sinned. Therefore, when called, it will be necessary for each person to examine their conscience and repent; and then be baptized when Jesus and His disciples call them to convert to Christianity. Not only were they to repent and be baptized, but they also had to convert for the Messiah had come!
The Bible does not contain anything against the baptism of infants.
Since these “rules and regulations” are written for adults that are recorded from adults’ interactions with Jesus and the Apostles in the New Testament they cannot apply in exactly the same way the same to infants who live under different circumstances.
Infants are new to the world and the only sin they have against them is the Original Sin. An infant is not old enough to be able to sin against God for they have not even come close to the age of reason. In order to read the Scriptures one must have some sort of adult comprehension and reading level to obtain a basic understanding.
Now, someone might come back with the argument that infants also are not old enough, or of the age of reason, to have faith in Jesus Christ. In light of that argument one should keep in mind two key points: one must have a comprehension like that of the people of the New Testament to fall under the same criteria for Biblical adult baptism and that Jesus was sent by the Father so that anyone who obeys Him and does the will of the Father will be saved (Cf. John 3:16-18, John 6:40).
Anyone includes all people. It means that the Kingdom of God is open to all people who meet the above stated criteria, which includes infants for they are people just as we are people and one’s grandparents are people.
Since the Kingdom of God is open to anyone who seeks and believes in Christ and since baptism is a necessity for entrance into the Kingdom (Cf. John 3:5) and since infants do not have the same comprehension level as adults nor have they reached the age of reason then the provisions for infant baptism must be different than the ones for adult conversion and baptism.
However, this does not mean that infants do not get the same effects as an adult baptism because it is still the act of baptism.
The Bible tells us in John 21:25 that there are many things that Jesus did, but are not contained in the Scriptures. Recall that in order to read the Scriptures one must have some sort of adult comprehension level (Cf. Paragraph 2).
Ponder the following question: why would the Scriptures instruct someone how to be baptized as an infant if they had already passed that stage of their life? Second Thessalonians 2:15 says, “Therefore, brothers, stand firm and hold to the teachings we passed on to you, EITHER by word of mouth [oral statement] OR by letter [letter of ours],” emphasis added.
This verse also shows that there are some things that are not written and that things handed down (i.e. tradition) are just as good as those that are written.
Infant baptism is one of the traditions that was handed down, but not recorded in the Scriptures.
Jesus handed it down to His disciples as one of the unwritten events (Cf. John 21:25) for the disciples to practice and hand on to their successors. It was passed down as a tradition carried out by the disciples as instructions on how to baptize infants.
Infant baptism is a tradition and practice of the early Church that is just as valid then, now and will be forever.