Where is legalism creeping in?

CJ Mahaney in his book the Cross Centered Life defines legalism as

"..seeking to achieve forgiveness from God and acceptance by God through obedience to God."

and this thought can creep in so subtly, whether it's missing a Bible reading in the morning or committing that same sin again, we can think in those moments that God loves me less. But the reality is, when we come to Christ, repenting of our sin and trusting in Jesus full and final payment for all my sin, the wonderful truth is that God sees me in Christ as one who has always obeyed. As Jerry Bridges describes in his book, the Gospel for Real Life,

"...all that Christ did in his life and death is effective for us because we are legally united to Him."

And so instead of looking at obedience as our way of keeping our righteous standing before God, let us consider it instead our obedience as opportunities for us to express our love to God for His Son with our lives. Legalism sees Christ's death as insufficient but Christ calls us to remember His cry from the cross. "It is finished!" Our full and final forgiveness is settled through the death of Jesus and through His perfect sacrifice, His perfect life is transfered to us.

So, where is legalism creeping in for us?