As Eireann one word can make a difference as in this case, the quote is “and” not " to" believe. Also, Agricola gave a very good definition of what to repent means.
I would like to add that although your wording may have been off, in a real way you caught the meaning. In the Greek of Mark, from which, as Eireann pointed out, the word used is “Metanoia”. This implys that one not only recognizes his sinfulness and seek forgiveness, but that one has to make a complete change in ones lifestyle and thinking. Only then can one truely be open to faith (Belief) in the Good News Christ Jesus was proclaiming. That News was, and is, God’s Kingdom (God’s active presence in the world and where God’s will is operative) is present here and now.
So I would say you caught the spirit because we have to have this metanoia to believe.