My take on this is the true church are those who think and act like Jesus. Those who accept His sacrifice for their sins and repent, believe and follow Him. There are true believers in every denomination and I don't think we will know the True Church until there are only two groups of people.
Those who will follow Jesus unto death if necessary and those who do not believe or follow Jesus.
“And he said unto them, Go ye into all the world, and
preach the gospel to every creature. He that believeth and is baptized shall be saved; but he that believeth not shall be damned.”
Mark 16:15-16 KJV
The body of Christ ( the church )
“Then Peter said unto them,
Repent, and be baptized every one of you in the name of Jesus Christ for the remission of sins, and
ye shall receive the gift of the Holy Ghost. ( spirit of Christ )
For
the promise is unto you, and to your children, and to all that are afar off, even
as many as the Lord our God shall call.
Then
they that gladly received his word were baptized: and the same day there were added unto them about three thousand souls.
And they
continued stedfastly in the apostles' doctrine and
fellowship, and in
breaking of bread, and in prayers. And fear came
upon every soul: and many wonders and signs were done by the apostles.
And
all that believed were together, and had all things common; and sold their possessions and goods, and parted them to all men, as every man had need.
And
they, continuing daily with one accord in the temple, and breaking bread from house to house, did eat their meat with gladness and singleness of heart, praising God, and having favour with all the people. And
the Lord added to the church daily such as should be saved.”
Acts 2:38-39, 41-47 KJV
“Know ye not, that
so many of us as were baptized into Jesus Christ were baptized into his death? Therefore we are buried with him by baptism into death: that like as
Christ was raised up from the dead by the glory of the Father, even
so we also should walk in newness of life.”
Romans 6:3-4 KJV
“For
as many of you as have been baptized into Christ have put on Christ. There is neither Jew nor Greek, there is neither bond nor free, there is neither male nor female: for
ye are all one in Christ Jesus. And
if ye be Christ's, then are ye Abraham's seed, and heirs according to the promise.”
Galatians 3:27-29 KJV
“And because ye are sons,
God hath sent forth the Spirit of his Son into your hearts, crying, Abba, Father.”
Galatians 4:6 KJV
the body of Christ is why we are baptized in his name , it’s why we take communion remembering his body and blood , it’s why we pray in his name , it’s why we receive his spirit , why we spread his word ect
anyone who hears and believes the true gospel that he sent into the world for salvation and acts upon that faith is a member of the body of Christ.
“the body of Christ” is another way to say the church.
His flesh and blood , his spirit , his word , his name