Something what I learned about churches while I was still in Germany comes to my mind. We say in German:

Missionsgemeinden sind bluehende Gemeinden!

The meaning of that sentence is that evangelizing churches and witnessing churches are thriving, flourishing churches.

Alban Douglas in his book “One hundred Bible Lessons” is listing four purposes of the church on page 177:

1. To worship God and glorify him on earth. Ephesians 1:4-6

2. To evangelize the world with the Gospel. Matthew 28:19,20

3. To teach and instruct Christians.  Ephesians 4:11-15

4. To witness constantly. Acts 1:8