I believe that salvation is accomplished by grace alone through faith alone in Christ alone (Ephesians 2:8-10). But salvation is more than a formula and more than “asking Jesus into my heart.” We consider the cost and we jump full in or we don’t jump at all. One of my mentors said it best: “Three things will surprise me in heaven: Who’s there; who’s not there; and that I’m there.” I think we’ll be surprised especially by all of the vacancies in heaven we thought would have been filled by people we knew who claimed to know Christ (Matthew 7:21-23).
On the other hand, while I emphasize and administer water baptism in my church (and I was baptized in my teens) I do not believe that water baptism plays a role in salvation. Although water baptism is sometimes mingled with salvation language in the New Testament; sometimes it is not included at all in salvation language in the New Testament. I would encourage you to listen to my sermon (or read it, someone has transcribed it) called “Baptism: A Flood of Confusion” on www.bible.org at this link (and we may have to agree to disagree on this one):