Baptism is a ceremonial washing in obedience to the command of Jesus Christ to show what is happening by faith and is the entrance into the visible Church.
Here are God’s Eternal Promises on Baptism:
What shall we say then? Shall we continue in sin that grace may abound? Certainly not! How shall we who died to sin live any longer in it? Or do you not know that as many of us as were baptized into Christ Jesus were baptized into His death? Therefore we were buried with Him through baptism into death, that just as Christ was raised from the dead by the glory of the Father, even so we also should walk in newness of life. For if we have been united together in the likeness of His death, certainly we also shall be in the likeness of His resurrection, knowing this, that our old man was crucified with Him, that the body of sin might be done away with, that we should no longer be slaves of sin. For he who has died has been freed from sin. Now if we died with Christ, we believe that we shall also live with Him, knowing that Christ, having been raised from the dead, dies no more. Death no longer has dominion over Him. For the death that He died, He died to sin once for all; but the life that He lives, He lives to God. Likewise you also, reckon yourselves to be dead indeed to sin, but alive to God in Christ Jesus our Lord. (Romans 6:1-11)
And He said to them, “Go into all the world and preach the gospel to every creature. He who believes and is baptized will be saved; but he who does not believe will be condemned. (Mark 16:15-16)
And Jesus came and spoke to them, saying, “All authority has been given to Me in heaven and on earth. 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, teaching them to observe all things that I have commanded you; and lo, I am with you always, even to the end of the age.” Amen. (Matthew 28:18-20)
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. For the promise is to you and to your children, and to all who are afar off, as many as the Lord our God will call.” (Acts 2:38-39)
Now as they went down the road, they came to some water. And the eunuch said, “See, here is water. What hinders me from being baptized?” Then Philip said, “If you believe with all your heart, you may.” And he answered and said, “I believe that Jesus Christ is the Son of God.” So he commanded the chariot to stand still. And both Philip and the eunuch went down into the water, and he baptized him. (Acts 8:36-38)
Then Peter opened his mouth and said: “In truth I perceive that God shows no partiality. But in every nation whoever fears Him and works righteousness is accepted by Him. The word which God sent to the children of Israel, preaching peace through Jesus Christ—He is Lord of all— that word you know, which was proclaimed throughout all Judea, and began from Galilee after the baptism which John preached: how God anointed Jesus of Nazareth with the Holy Spirit and with power, who went about doing good and healing all who were oppressed by the devil, for God was with Him. And we are witnesses of all things which He did both in the land of the Jews and in Jerusalem, whom they killed by hanging on a tree. Him God raised up on the third day, and showed Him openly, not to all the people, but to witnesses chosen before by God, even to us who ate and drank with Him after He arose from the dead. And He commanded us to preach to the people, and to testify that it is He who was ordained by God to be Judge of the living and the dead. To Him all the prophets witness that, through His name, whoever believes in Him will receive remission of sins.” While Peter was still speaking these words, the Holy Spirit fell upon all those who heard the word. And those of the circumcision who believed were astonished, as many as came with Peter, because the gift of the Holy Spirit had been poured out on the Gentiles also. For they heard them speak with tongues and magnify God. Then Peter answered, “Can anyone forbid water, that these should not be baptized who have received the Holy Spirit just as we have?” And he commanded them to be baptized in the name of the Lord. Then they asked him to stay a few days. (Acts 10:34-48)
Now there was a certain disciple at Damascus named Ananias; and to him the Lord said in a vision, “Ananias.” And he said, “Here I am, Lord.” So the Lord said to him, “Arise and go to the street called Straight, and inquire at the house of Judas for one called Saul of Tarsus, for behold, he is praying. And in a vision he has seen a man named Ananias coming in and putting his hand on him, so that he might receive his sight.” Then Ananias answered, “Lord, I have heard from many about this man, how much harm he has done to Your saints in Jerusalem. And here he has authority from the chief priests to bind all who call on Your name.” But the Lord said to him, “Go, for he is a chosen vessel of Mine to bear My name before Gentiles, kings, and the children of Israel. For I will show him how many things he must suffer for My name’s sake.” And Ananias went his way and entered the house; and laying his hands on him he said, “Brother Saul, the Lord Jesus, who appeared to you on the road as you came, has sent me that you may receive your sight and be filled with the Holy Spirit.” Immediately there fell from his eyes something like scales, and he received his sight at once; and he arose and was baptized. (Acts 9:10-18)
And now why are you waiting? Arise and be baptized, and wash away your sins, calling on the name of the Lord.’ (Acts 22:16)
‘…And it shall come to pass that whoever calls on the name of the Lord shall be saved.’ (Acts 2:21)