Nicodemus was very religious. And this was a major obstacle preventing him from receiving the teaching and understanding the message of Jesus.
Here’s a wonderful contrast between RELIGION and THE GOSPEL by Tim Keller:
RELIGION: I obey, therefore I’m accepted.
THE GOSPEL: I’m accepted, therefore I obey.
RELIGION: Motivation is based on fear and insecurity.
THE GOSPEL: Motivation is based on grateful joy.
RELIGION: I obey God in order to get things from God.
THE GOSPEL: I obey God to get to God, to delight and resemble him.
RELIGION: When circumstances in my life go wrong, I am angry at God or myself, since I believe, like Job’s friends that anyone who is good deserves a comfortable life.
THE GOSPEL: When circumstances in my life go wrong, I struggle but I know all my punishment fell on Jesus and that while he may allow this for my training, he will exercise his fatherly love within my trial.
RELIGION: When I am criticized, I am furious or devastated because it is critical that I think of myself as a “good person.” Threats to that self-image must be destroyed at all costs.
THE GOSPEL: When I am criticized, I can take it. I struggle, but it is not critical for me to think of myself as a “good person.” My identity is not built on my record or my performance, but on God’s love for me in Christ.
RELIGION: My prayer life consists largely of petition and only heats up when I am in a time of need. My main purpose in prayer is control of my environment.
THE GOSPEL: My prayer life consists of generous stretches of praise and adoration. My main purpose is fellowship with God.
RELIGION: My self-view swings between two poles: If and when I am living up to my standards, I feel confident, but then I am prone to be proud and unsympathetic to failing people. If and when I am not living up to standards, I feel insecure, inadequate, and not confident. I feel like a failure.
THE GOSPEL: My self-view is not based on a view of myself as a moral achiever. In Christ I am “simul iustus et peccator”—simultaneously sinful and yet accepted in Christ. I am so bad he had to die for me and I am so loved he was glad to die for me. This leads me to deeper and deeper humility and confidence at the same time, neither swaggering nor sniveling.
RELIGION: My identity and self-worth are based mainly on how hard I work or how moral I am, and so I must look down on those I perceive as lazy or immoral. I disdain and feel superior to “the other.”
THE GOSPEL: My identity and self-worth are centered on the one who died for his enemies and who was excluded from the city for me. I am saved by sheer grace, so I can’t look down on those who believe or practice something different from me. It is only by grace that I am what I am. I have no inner need to win arguments.
RELIGION: Since I look to my own pedigree or performance for my spiritual acceptability, my heart manufactures idols. It may be my talents, my moral record, my personal discipline, my social status, etc. I absolutely have to have them so they serve as my main hope, meaning, happiness, security, and significance, regardless of what I say I believe about God.
THE GOSPEL: I have many good things in my life: family, work, spiritual disciplines, etc. But none of these good things is an ultimate end for me. None of them is something I absolutely have to have, so there is a limit to how much anxiety, bitterness, and despondency such things can inflict on me when they are threatened and lost.