We major on the minor things and minor on the major things way too often. I’m one of the worst. My family would tell you that I let the small things bother me while tolerating larger issues. Dust on the lamp bothers me but overgrown bushes, I can live with. Thank goodness my boys are good in the yard. We do this with our faith as well. Jesus said to the Pharisees, “You strain out a gnat but swallow a camel”. We make big deals out of the small personal preference issues like style of worship and ignore larger issues like baptism. And when someone is really big on something as important as baptism, there is always someone who will say. It’s not necessary because of the thief on the cross was saved without being baptized. Why should I be baptized? I’ve made similar statements before myself. 
But, just because you could theoretically get into Heaven without being baptized, does that mean that you should try it? Jesus demonstrated how to begin with God by being baptized Himself. The Father and the Holy Spirit showed up for His baptism and they will also show up for yours if you haven’t been baptized already. Then of course, Jesus said that we should baptize in the name of The Father, The Son and The Holy Spirit. In fact, those were His last words to the disciples before His ascension. He said to make disciples by doing two things, teach them to obey all that Christ commanded and baptize them. That’s it. Simple but powerful. If commitment is lacking in your life, maybe you should consider beginning again with baptism even if you were baptized once before.