Acts 20: 28: “Be on guard for yourselves and for all the flock, among which the Holy Spirit has made you overseers, to shepherd the Church of God which He purchased with His own blood.” So, you’re looking for another verse that supports the doctrine of the Trinity? To Whom do the pronouns ‘He’ and “His’ refer in this verse? It can’t be the Holy Spirit, for He has no blood. The only other Deity mentioned in the sentence, or anywhere near the sentence, is ‘God’. But could this ‘God’ be referring to God the Father? Again, He has no blood, He is a Spirit (John 4: 24). The One Who purchased the Church with His own blood, Who owns the Church, is Jesus Christ – Who is here called God. Trinity!