There are stages of every Christian life: Justification (salvation), Sanctification (working out our salvation) and Glorification (heaven).
Working with worship songs and songwriters, I hear a lot of songs about salvation and heaven, but not as many about sanctification. I believe there is certainly a need for songs that address all three. We need to praise God for salvation, even singing to the lost how God has saved us. We also need to look ahead at times to heaven when we will finally worship Jesus face to face.
However, there's a whole lot of life that happens in between salvation and heaven, and it's critical that we write and sing songs that deal with life as a Christian. I think our songwriting may point to a larger issue within the church, that we've gotten really good at teaching what it means to be saved, but we struggle to teach life transformation.
We need more songs on what it means to love one another. We need more songs about being faithful to our families. We need more songs about generosity. We more songs about standing up for the weak and hurting.
These things may not be as fun to sing or preach about, but our churches are desperate to know what it means to be a follower of Christ.