The Church did not begin her existence till the descent of the Holy Ghost at Pentecost (Acts 2). However, as a model of Catholic laity, the Good Thief is a fitting example: he repented of his sin, accepted his punishment, grew in virtue as he defended the innocently accused and defended the Lord against blasphemy, was baptized by his suffering, and asked Christ to bless him.
The story of the Good Thief serves another purpose as well: it shows that some people are prevented from receiving a baptism and can be saved extraordinarily. Likewise, if someone cannot receive the sacraments of the Church because of a physical impediment, the sacraments will be brought to him, or if for some reason that cannot be done either, he should not despair of his salvation in the Church despite the physical separation.
it was to be the churches job to teach this gospel
That is not the only job. The Church was told to proclaim the gospel and to baptize (Mark 16:15-16), to forgive sins (John 20:21-23), to offer the Holy Eucharist (Luke 22:19), to legislate supremely (Matthew 18:18), to correct heresies (Luke 22:31-32), and generally to guide people to salvation (Matthew 18:19).
And alll you quote in no way hands over to flesh man the power to save anyone. There are 7 churches identified as to what they teach and who finds 'favor' and who is left wanting. Christ is the key of David which no man shutteth and no man openeth, does your church teach this?
How can the church start at Pentecost? If it was something new, why were three thousand ADDED to the church? Peter at Pentecost is not telling Israel that Jesus died for their sins. He’s telling them they killed their Messiah. He’s not preaching the cross as good news. He’s preaching a murder indictment against Israel.