I am not interested in what other say, I am only interested in what Bible says.
Notice what Jesus said:
Matthew 28:19 "Go therefore and make disciples of all the nations, baptizing them in the name of the Father and of the Son and of the Holy Spirit, 20 "teaching them to observe all things that I have commanded you;
The Great Commission as it is called has Jesus telling us how to make disciples of Christ. Jesus also said:
Mark 16:16 "He who believes and is baptized will be saved; but he who does not believe will be condemned.
Jesus said that belief and baptism are required to be saved. You cannot grammatically separate these two things because they are bound together by the word and. Jesus disciples did not disappoint because at the birth of the church in Acts 2 Peter told the Jews exactly what they needed to do be saved:
Acts 2:38 Then Peter said to them, "Repent, and let every one of you be baptized in the name of Jesus Christ for the remission of sins; and you shall receive the gift of the Holy Spirit.
Again, you cannot separate these two things and baptism is the point at which your sins are forgiven. Hence no baptism, no forgiveness of sins. Just read through the book of acts and you will find two things that are mentioned when someone was converted to Christ: belief and baptism.
There is nothing magical about the water, it simply the place God has said you will come in contact with the cleansing power of Jesus blood (Rev. 1:5). Being baptized is not a work of man, but a work of God. As Paul says:
Colossians 2:11 In Him you were also circumcised with the circumcision made without hands, by putting off the body of the sins of the flesh, by the circumcision of Christ, 12 buried with Him in baptism, in which you also were raised with Him through faith in the working of God, who raised Him from the dead. 13 And you, being dead in your trespasses and the uncircumcision of your flesh, He has made alive together with Him, having forgiven you all trespasses,
When you submit yourself to baptism and put your faith in the working of God, you can know that you are being buried with Christ and united in His death. Your old man is being put to death (Rom. 6) and God is washing away your sins with the blood of Jesus (Just like Paul Acts 22:16). When you come up from the water you can know that you have been raised from spiritual death caused by your sin and you been raised alive together with Jesus as a new creature in Christ without your sins.
Since you must put faith in the working of God for this to happen, it means you must know what you are doing, which rules out being baptized as baby or young child without understanding.
This why Peter said:
1 Peter 3:21 There is also an antitype which now saves us -- baptism (not the removal of the filth of the flesh, but the answer of a good conscience toward God), through the resurrection of Jesus Christ,
Peter couldnt make it clearer baptism is necessary for salvation and it is an answer of good conscience to God, which means we must know what we are doing when are being baptized, otherwise we just get wet.
The Bible, not me, teaches that baptism is necessary for salvation.