God did not really give him a new identity. He revealed to him his original blueprint, what his heart had all along been designed to be. The deceiver Jacob was a false self created and perpetuated by himself and his mother in wrong reactions to pressuring circumstances. Jacob's heart had always yearned for intimacy with God but the lies embedded early caused him to act out in sins which created shame which produced more lies which produced more shame and anger and pain.
We too must realize and feel a desperate, passionate hunger for God Himself that eclipses every other craving and pleasure. This is the whole explanation of “Jacob's time of trouble” in the end. It is , pure and simple, an abandonment of every lie, every other source that we have tried to use to receive life and love and satisfaction. It is getting real about every emotion, feeling and belief we have stuffed, ignored, suppressed or tried to deny or escape from. We finally become fully honest and transparent and hopeless, realizing that our only source for any sense of value and love must come directly to our heart from God alone.
It is not about a focus on achieving perfection and forcing ourself to overcome every sin like many of us have grown up to believe. It is about embracing our guilt, our pain and facing our lies about God and about ourself full face. It is only at that point that we can fully appreciate the totality of our hopelessness and bankruptcy and full embrace His grace and rest completely in His righteousness alone to redeem us.