There can be no doubt baptism is necessary. As explained in the Book of Mormon:
And now, if the Lamb of God, he being holy, should have need to be baptized by water, to fulfil all righteousness, O then, how much more need have we, being unholy, to be baptized, yea, even by water! And now, I would ask of you, my beloved brethren, wherein the Lamb of God did fulfil all righteousness in being baptized by water? Know ye not that he was holy? But notwithstanding he being holy, he showeth unto the children of men that, according to the flesh he humbleth himself before the Father, and witnesseth unto the Father that he would be obedient unto him in keeping his commandments. Wherefore, after he was baptized with water the Holy Ghost descended upon him in the form of a dove. And again, it showeth unto the children of men the straitness of the path, and the narrowness of the gate, by which they should enter, he having set the example before them. And he said unto the children of men: Follow thou me. Wherefore, my beloved brethren, can we follow Jesus save we shall be willing to keep the commandments of the Father? And the Father said: Repent ye, repent ye, and be baptized in the name of my Beloved Son. (2 Ne. 31:5-11.)
It is required of us for our salvation because Christ made it so and the scriptures unequivocally state that is the case. There is no question about its necessity. The only question is: is your baptism sufficient as the Lord is preparing for His return? Ask yourself these simple questions: Would you be willing to participate in a rite designed by God to show you have repented? Is there any merit for you to establish a record today to show that you have repented? Do you acknowledge baptism a required sign requested by God for us to perform as a sign of our repentance?
Remember the Lord’s warning in 1831: “I say, hearken unto my voice, lest death shall overtake you; in an hour when ye think not the summer shall be past, and the harvest ended, and your souls not saved.” (D&C 45:2.)
Recall Jeremiah’s vision of the end when the Lord returns again: “Is not the Lord in Zion? is not her king in her? Why have they provoked me to anger with their graven images, and with strange vanities? The harvest is past, the summer is ended, and we are not saved.” (Jer. 8:19-20.) “Graven images” can include anything and anyone which offers itself up as an object of devotion supplanting Christ. “Strange vanities” include well reasoned arguments fashioned to build up false faith or tear down true faith. Either one will leave us unsaved at the coming harvest if we do not repent, and accept the terms Christ established, including baptism.
Please consider whether the day may come when you may want to have been baptized to show your current repentance by the act Christ established as necessary for everyone’s salvation. Even His own.