If Ukraine joins NATO, it will be a solid move towards the west and away from Russia. It would establish stability and give a sense of security to the country. Russia doesn't want Ukraine to join NATO because of this fact. In order for Ukraine to remain a united country, stability and security are needed from the outside as well as from within Ukraine.
The West should offer NATO membership to Ukraine in order to prevent the spread of the influence of Russia in the region. Russia has shown aggression in recent years, and it's important for the West to stop the spread of Putin's dictatorial power. NATO membership will help us gain an important ally in central Asia.
Ukraine has had numerous issues with corruption in its elections and, later, with its elected officials. Until they can more consistently provide free, fair, transparent elections to their people, it would be an unfair burden upon NATO to ask them to protect a government whose legitimacy might be called into question.