If anyone adds ANYTHING to what Jesus has done and believes it is necessary for salvation, they are not saved. It is Jesus and His finished work of redemption alone. Baptism is the first step of obedience for the new believer. Check out Acts 8:37 - the Ethiopian Eunuch got baptized because he already believed in Jesus Christ with all his heart. Romans 6 teaches that baptism is a picture of Jesus' death, burial and resurrection - it is a public statement of your faith in Him and an indentification with what He has done to save you. It adds nothing to salvation. Your place in eternity is determined by what you do with Jesus, not whether you have Jesus + something else. Also, the Bible clearly teaches we are not saved by any works (works of the law, works of righteousness - but solely by God's grace received through our faith in Jesus's finished work on the cross - and this verse shows that baptism is a work of righteousness:

Matthew 3:15 And Jesus answering said unto him, Suffer it to be so now: for thus it becometh us to fulfil all righteousness. Then he suffered him.

Titus 3:4-7 But after that the kindness and love of God our Saviour toward man appeared, Not by works of righteousness which we have done, but according to his mercy he saved us, by the washing of regeneration, and renewing of the Holy Ghost; Which he shed on us abundantly through Jesus Christ our Saviour; That being justified by his grace, we should be made heirs according to the hope of eternal life.

Romans 4:3-6 For what saith the scripture? Abraham believed God, and it was counted unto him for righteousness. Now to him that worketh is the reward not reckoned of grace, but of debt. But to him that worketh not, but believeth on him that justifieth the ungodly, his faith is counted for righteousness. Even as David also describeth the blessedness of the man, unto whom God imputeth righteousness without works,

Philippians 3:9 And be found in him, not having mine own righteousness, which is of the law, but that which is through the faith of Christ, the righteousness which is of God by faith:

Trace out the word "righteousness" in the NT and see how it is obtained: through faith, not works. Isaiah 64:6 shows that man's righteousness is as filthy rags in God's sight - could never earn or merit salvation - therefore it must only be through God's righteousness credited to our account. See Jeremiah 23:6.