These are the two consistents we expect to see in one another as we open God’s word. Christians are always repenting, always changing, always transforming, always growing. There is a right concern we should have when we meet a Christian who keeps repentance at an arms length away and repents irregularly.
At the same time, Christians always have reason to be rejoicing, thankful, hopeful, content. Again, it’s appropriate to be concerned for the Christian who doesn’t want to rejoice, or avoids it.
The beauty of the gospel is that these two are not extremes in tension. The gospel calls me to a forgiving God in whom we rejoice in our repentance!