repenting is to change our thinking, This is what changes our actions.
Repenting is not living up to a set of rules and regulations, and thinking your spiritual and blessed by God. As paul said, A gentile who does not know Christ can by nature obey the laws of God without even having the law. So obeying some law to some standard to make God happy with you, and try to earn his love is legalism. It is self motivated, not out of love.
God said we have all sinned and fall short of his glorious standard (literally missed the mark) No one can live up to Gods standard and be worthy of eternal life.
Saying this does not promote a sinful lifestyle Saying it does not saying it is ok to sin, Saying it is admiting a fact of spiritual truth.
Those who love God because they experienced his true love wil follow him, and learn to love his ways, and in doing so will follow his commands.
Those who follow his commands to get something out of it, will also follow his commands.
Sadly. Niether will be able to live up to Gods standards, and fall short of the glory of God. The only thing is left is redemption, which was paid by the blood of Christ, His sweat, His body, His life, His sacrifice. NOTHING we have done, are doing or will ever do will make us worthy of his sacrifice or his love, for we all fall short.
Legalsim is dangerous because it acts in carnality (I do this so God must love me) where Grace kids act in love and appreciation for God (I do not do it to earn anything, for I do not deserve anything to begin with, I do it, Because I trust God, and his ways, and have rejected myself and my ways.