There are three types of baptism... sprinkling of water, pouring of water and the last one, immersion. And does baptism ensure you a sure ticket to heaven? The answer is no. People are saved through believing in Jesus Christ and putting their faith in Him. And why should be baptized? There are some passages from the bible explains this.
for all of you who were baptized into Christ have clothed yourselves with Christ.
1 Peter 3:21
and this water symbolizes baptism that now saves you also—not the removal of dirt from the body but the pledge of a good conscience toward God. It saves you by the resurrection of Jesus Christ,Baptism is not an outward cleaning, but saves us through an inward cleaning. It is an appeal to God for a good conscience and asks God to take away the guilt of our past sin.