I have always felt some tension about using the church's common lectionary. By its very nature a lectionary divides texts into chunks deemed to be the right size for reading in a worship service, with one theme around which a preacher might develop a sermon. Whether the text for one week follows in a logical sequence from that of the previous week is not the primary concern of a lectionary. But this becomes an acute problem when reading the epistles of Paul, who wrote actual letters to real people in congregations, and who meant for them to be proclaimed to a congregation as an entire speech from start to finish. In many cases, a block of five to 10 verses may have been only a small point within a much larger Pauline argument.
The piecemeal approach may work better in, say, 1 Corinthians, where Paul responds to various issues and questions that have been raised by the squabbling Corinthians themselves. But Romans is clearly composed of a single argument, and to miss one major proof, such as that in chapters 9-11, is to miss Paul's overall thrust.
A second tension arising from lectionary use is the unspoken assumption that a chosen text can be directly applicable to contemporary Christian life. It is no doubt true that lectionary texts are selected on the basis of timeless relevance. I notice, for example, that none of the 19 lectionary texts from Romans that will be read in Cycle A come from the opening greetings in chapter 1, nor from the closing chapters where Paul discusses his future plans and greets many individuals and house church groups. This, however, already skews the meaning of the texts that are chosen, implying that Paul wrote a general theological treatise for all Christians in all times and places—something he most certainly did not do!