Mark 16:16 and Acts 2:36-41 both declare that we must be baptized to be saved....does this mean water baptism a requirement for salvation?
Regarding Mark 16:16, Acts 2:36-41, and others like them, these are often misunderstood as commanding water baptism to be saved, but this is not what the text is teaching. Any teaching that declares a human work to be a necessary requirement for salvation contradict the clear and consistent teaching of the New Testament, perhaps best summed up by Paul in Romans:
Rom. 4:5: But to the one who does not work, but believes in Him who justifies the ungodly, his faith is credited as righteousness
Rom. 10:9-10: that if you confess with your mouth Jesus as Lord, and believe in your heart that God raised Him from the dead, you will be saved; for with the heart a person believes, resulting in righteousness, and with the mouth he confesses, resulting in salvation.
If these passages had intended to make water baptism a requirement for salvation, then the Bible would be contradicting itself, and we know that God never contradicts Himself (1Sam 15:29).
Fortunately, there is no contradiction, because these passages do not teach that you must receive water baptism to be saved. Instead, these passages are calling saving faith by means of the baptism of the Holy Spirit. The baptism of the Holy Spirit (sometimes just called "baptism) is the moment of saving regeneration in our spirit that accompanies (and enables) our confession of Christ.
It is impossible to believe the Gospel and be saved without the baptism of the Holy Spirit, which causes us to be born again, according to John 3. We can read about the baptism of the Holy Spirit in many passages in the New Testament. For example, John the Baptist talks of the coming baptism of the Holy Spirit in Mark 1:8 and John 1:33. Jesus talks about it in Mark 10:38-39 and again after His resurrection in Acts 1:5. Peter talks about this new baptism in Acts 11:16.
Paul talks about this baptism in Rom 6:3-4, 1Cor 12:13, Gal 3:27, Eph 4:5, and Col 2:12. These are all references to the saving work done by the Holy Spirit in the heart of every believer, which we call the "baptism of the Holy Spirit" or sometimes just "baptism."
Remember, water baptism is merely a sign of something greater. Paul teaches in Romans 6 and 1Cor 15 that water baptism is a picture of how we died with Christ through the baptism of the Holy Spirit and how we will rise again with Him one day. When we experience water baptism by going under the surface of the water, we picture our spiritual death through Christ's death on the cross (i.e., going down into the grave with Christ). When we come up out of the water, we picture our future resurrection in Christ. Therefore, the act of water baptism is an outward sign of the inward change accomplished by the baptism of the Holy Spirit.
Interestingly, both Peter and Paul make clear that water baptism is NOT a requirement for salvation in their letters. First, Paul says explicitly that Jesus did NOT send him to water baptize people, but instead to preach the Gospel for the salvation of men:
1Cor. 1:14 I thank God that I baptized none of you except Crispus and Gaius,
1Cor. 1:15 so that no one would say you were baptized in my name.
1Cor. 1:16 Now I did baptize also the household of Stephanas; beyond that, I do not know whether I baptized any other.
1Cor. 1:17 For Christ did not send me to baptize, but to preach the gospel, not in cleverness of speech, so that the cross of Christ would not be made void.
If water baptism were required for salvation, wouldn't we expect Paul to make the opposite claim in 1Cor 1:17? Wouldn't Paul have emphasized that he performed water baptism on many believers since it was essential to their salvation? Instead, Paul says he's glad he didn't baptize many with water. Clearly, Paul did not think water baptism was a means to salvation, and his words in 1Corinthians indicate that water baptism can be overemphasized in an inappropriate way.
Furthermore, consider Paul's own conversion and water baptism. In Acts 9 we find that as Paul arrives in Ananias' house, we're told Paul had been saved and appointed to become Jesus' instrument to bring the Gospel to the Gentiles. At that point, Paul had yet to be water baptized, yet Scripture says he was already saved. Obviously, in Paul's own conversion, salvation occurred before his water baptism.
Next, Peter says in 1Pet 3:21 that water baptism is not what saves a person:
1Pet. 3:21 Corresponding to that, baptism now saves you — not the removal of dirt from the flesh, but an appeal to God for a good conscience — through the resurrection of Jesus Christ,
Peter makes clear that the baptism he's talking about in v.21 that saves is NOT the baptism of water (i.e., the one which removes dirt from the flesh). Rather, men are saved by an appeal to God for a good conscience, Peter says, which refers to our spiritual baptism. Such an appeal is made possible by the baptism of the Holy Spirit (1Cor 12:3), so we could translate Peter's words as, "...baptism saves you - not water baptism but the baptism of the Holy Spirit..."
Finally, consider these additional reasons why we know water baptism cannot be a prerequisite to salvation:
1. The thief on the cross was declared saved by Christ, yet we know the thief never experienced water baptism before he died. If even one man can go to heaven without water baptism, then it disproves the teaching that Mark 16:16 makes water baptism a requirement for salvation.
2. The OT saints like Abraham never experienced any form of water baptism, yet the Bible tells us they were saved. In fact, they were saved in the same way we are saved: by faith alone. Paul clearly and specifically teaches in Romans 4 that Abraham believed God and it was credited to him as righteousness. Abraham was declared righteous (i.e., saved) by faith without any requirement for water baptism. Again, if the OT saints could be saved by faith without the requirement for water baptism, then we can know that Mark 16:16 is not teaching that water baptism is a requirement for salvation.
3. In Acts 10, Peter declares that the church leadership shouldn't withhold the opportunity for water baptism from Gentiles who had already received the indwelling of the Holy Spirit (Acts 10:47). Elsewhere, Paul tells us that the definition of a true Christian is anyone who is indwelled by the Holy Spirit (Rom 8:14). Therefore, according to Peter the Gentiles in Acts 10 were already indwelled by the Holy Spirit, which means they were already Christians - and yet they had not received water baptism at that point. Here again, we see clearly that water baptism is not a prerequisite for salvation.
There are many other examples like these in the Bible that prove that water baptism is not the essential requirement for salvation. Salvation is by faith alone in Jesus Christ, and this salvation is not by works so that no man may boast (Eph 2:8-9). This is truly Good News!
So why do we receive water baptism? Jesus commanded that every believer receives this sacrament as an outward sign of our spiritual baptism which is invisible (Matthew 28:18-20). Receiving water baptism is an important step of obedience that welcomes us into the family of God and readies us to follow the Lord with our whole heart. It forms our first - and best - testimony of our faith in Jesus Christ.
Since water baptism is the first act command of every believer by our Lord Christ, we should not underestimate the importance of our obedience. When a believer knowingly rejects water baptism, they rebel against the word of God and against the Lord Who saved them, and they risk beginning a life of disobedience in the faith with eternal consequences. Remember the words of the writer of Hebrews:
Heb. 3:12 Take care, brethren, that there not be in any one of you an evil, unbelieving heart that falls away from the living God.
Heb. 3:13 But encourage one another day after day, as long as it is still called “Today,” so that none of you will be hardened by the deceitfulness of sin.
Heb. 10:28 Anyone who has set aside the Law of Moses dies without mercy on the testimony of two or three witnesses.
Heb. 10:29 How much severer punishment do you think he will deserve who has trampled under foot the Son of God, and has regarded as unclean the blood of the covenant by which he was sanctified, and has insulted the Spirit of grace?
Heb. 10:30 For we know Him who said, “ VENGEANCE IS MINE, I WILL REPAY.” And again, “ THE LORD WILL JUDGE HIS PEOPLE.”
Heb. 10:31 It is a terrifying thing to fall into the hands of the living God.
The writer warns believers to consider the consequences of disobeying the living God by rejecting His commands. They are terrifying indeed. As a last resort in order to discipline those who willfully disobey the Lord, the church may cut off fellowship from the disobedient believer, so to those who refuse water baptism, the consequence is that the church removes them from fellowship.