The Church is referred to as the body of Christ. This Christ given symbolism can be taken as an analogy of what is expected of the Church. And, what is expected of the Church gives us some insight into its purpose.
(1 Cor 12:27 NIV) Now you are the body of Christ, and each one of you is a part of it.
(Eph 5:23 NIV) For the husband is the head of the wife as Christ is the head of the church, his body, of which he is the Savior.
(Col 1:18 NIV) And he is the head of the body, the church; he is the beginning and the firstborn from among the dead, so that in everything he might have the supremacy.
(Col 1:24 NIV) Now I rejoice in what was suffered for you, and I fill up in my flesh what is still lacking in regard to Christ's afflictions, for the sake of his body, which is the church.
We can note that the body consists of distinct members working for a common purpose, that is they are unified. Likewise we as distinct members should be unified. That unity should be found in Christ.
The body is ruled by the head and the head counts on the support of the members. Christ is that head and we are the members. Christ counts on our support.
The members are designed with different strengths and weaknesses for different tasks. The same is true for each of us. We work best as a unified body when we understand our strengths and weaknesses and coordinate them with the body at large.
All members of the body are necessary for the proper and complete functioning of the body. When one member is missing or not fully functional other members must try to make up the difference. Sometimes this is possible and sometimes it is not.
The body must interact with other bodies in the course of ordinary life. The same is true for the Church. Given that we are to love others as we love ourselves and that we are to live at peace with all men in as much as that may be possible, it follows that our actions and words must reflect those Christ-like dictates.
Given that God desires that none should perish and that Christ always works to please his father, it follows that we should feel the same way and act the same way.
Since we have the command to honor our father and mother it follows that even more so we should honor our heavenly Father.
So what then is the purpose of the Church based upon this symbolism and analogy? Although the symbolism and analogy could be greatly expanded and expounded upon, what we have is sufficient to point us in the right direction.
The purpose of the Church is simply to believe God and to do his will. This is manifested in our works, which is how we live our lives. Man does not live by bread alone, but by every word that proceeds from the mouth of God.
So, more specifically, here are a few of the things that fall under the umbrella of the, “Purpose of the Church.”
Setting a good example.
Helping our fellow man. Especially those in the body of Christ.
Sharing the good news of God and the coming kingdom.
Teaching the necessity of repentance and acceptance of Christ.
Remaining steadfast and appreciative under all circumstances.
Recognizing who we are and what we are from God’s perspective
In summary let me quote from Ecclesiastes 12:13 & 14.
Now all has been heard; here is the conclusion of the matter: Fear God and keep his commandments, for this is the whole duty of man. For God will bring every deed into judgment, including every hidden thing, whether it is good or evil.