I must have read the wrong bible when I’m hearing this. This talk about unmerited favor is more like over-unmerited favor. Favor is only talked about in a narrow idea of blessing which talks about promotions and gains.
Jesus tells us that to follow him is to take up the cross which implies a life where shame and suffering for the sake of Christ are facts for the Christian. 1 Peter talks about slaves which have to suffer through undeserving circumstances where Peter exhorts them about Jesus’ attitude towards suffering circumstances. Paul tells us also that those who want to live a godly life would suffer.
Prince may be a godly man and all that but his theology is narrow and one sided. The bulk of the NT is about how to live life in the midst of hostile environments. Following Christ does not entail a blissful ride where when we have activated faith in him, the floodgates of heaven will open. No. Following Christ means to crucify the self. But it does not entail a boring future. The promise of following Christ means the discovery of what life is supposed to be under the rule of God. And there is the promise of an everlasting future, where eternal life is possible through the resurrection of Christ.
An over emphasis on favor waters down the gospel into the unattainable promises laid out by advertisements. Playing too much on unmerited favor is an over-unmerited favor of a clueless god.