The concept of a need for unity implies at least three elements. First, there is a group. Second, they do not naturally unite. Third, there is a need to unify.
Gathering people for a single purpose, this is the first element of unity. Gathering a group of people for a singular spiritual purpose requires unity under One Lord, one faith, one baptism, one God and Father of all (Ephesians 4:4-6).
Individuality is a natural aspect of the human heart. Our desire for self or uniqueness is the struggle against dependent faith. Christ requires our trust in Him be complete. The first step in unity is faith; humbling ourselves and trusting someone we cannot see. Where a group submits in faith we find the second element fulfilled.
Jesus requires we unify and function like a body to serve Him. The reasons for this are multiple but essential. We serve God better. We are tempted less when accountable to others. We are not so easily deceived in groups as opposed to alone. We are, therefore stronger when gathered together under Christ than we are alone. We accomplish more together than apart. Unity is a work in Christ.
Church bodies develop from individuals called to a higher purpose. We are asked to forsake individuality and subject ourselves to Christ through that body of believers. We simply rest in our faith in Him as the body determines the direction. We are united in the hope of Christ through the Spirit. Therefore, though individuality is the typical response of natural man, unification under Christ is a natural response for the believer. We have a heavenly gift in Christ that provides the love, faith and desire to submit to and unify with one another.