There are many answers to the question in our heading, but the most frequent is to say: I need Jesus because I love Him. It would be great that we all need Jesus because in Him we discover that we are totally miserable, but the truth is that people seek Jesus for different reasons and seeking Him for love is the last of them.
Remember that when Jesus was in the world, many people followed Him for the miracles that He produced, others for the distribution of fish and bread, others to discuss issues of the law of Moses and thus find a way to make Him stumble and then accuse Him, also there were His 12 disciples and some pious women who looked for Him beyond all that He could do.
What group of people do we belong to? Do we only need Jesus to solve our problems, when we are sick, when we are in shortage? Do we only need the words of Jesus to debate some theological subject and then presume that we are endowed with all science? Why do we need Jesus?