Rome had occupied the Iberian Peninsula beginning in 200 BC, but it was during Paul’s lifetime that this area called Spain had been organized into a Roman province.  Spain was the location of the Old Testament Tarshish which was, at that time, the extent of the Western world, or “the ends of the earth.” Jesus had spoken of the disciples taking the Gospel from Jerusalem, to Judea, to Samaria and then, to the ends of the earth. Paul may have been thinking of fulfilling Jesus’ commission, and, most likely, he was thinking of the prophecy in Isaiah 66:19:

“I will set a sign among them, and I will send some of those who survive to the nations—to Tarshish, to the Libyans and Lydians (famous as archers), to Tubal and Greece, and to the distant islands that have not heard of my fame or seen my glory. They will proclaim my glory among the nations.” – Isaiah 66:19

Although the New Testament never records Paul going to Spain we do know there was time, support and motivation to accomplish this mission between Paul’s release from the Roman house arrest recorded at the end of Acts and his final imprisonment mentioned in Second Timothy. Clement, the pastor of the church of Rome wrote in 85 AD in his letter to the Corinthians (entitled First Clement):

“Let us place before our eyes the good Apostles. Peter, through unjust envy, endured not one or two but many labors, and at last, having delivered his testimony, departed unto the place of glory due to him. Through envy Paul, too, showed by example the prize that is given to patience: seven times was he cast into chains; he was banished; he was stoned; having become a herald, both in the East and in the West, he obtained the noble renown due to his faith; and having preached righteousness to the whole world, and having come to the extremity of the West, and having borne witness before rulers, he departed at length out of the world, and went to the holy place, having become the greatest example of patience.” – First Clement 5:3-7 written in Rome to Corinthian Church in 85 AD by Clement who is mentioned by Paul in Philippians 4:3

Paul tells the Romans that he hopes “to have you assist me on my journey there” to Spain. The Greek verb propempo that is translated in the English above as “assist” is a term that developed through use by the early church that took on a technical meaning used to refer to missionary support. Paul is planning on receiving financial and material support from the church in Rome when he writes this in 57 AD. It would appear Paul was in Spain sometime during the years 62-66 AD.

“Wherever we see the Word
of God purely preached
and heard, there a church
of God exists, even if it swarms with many faults.”
- John Calvin

Lateran Council (1215) - mandatory confession of sin
to a priest once a year