“Forgetting what lies behind and straining forward to what lies ahead” (Phil 3:13-14). 

We Have to Let it Go Because... 

1. What lies behind cannot be changed, corrected, or manipulated (Matt 27:3-10) — Judas regretted what he had done, tried to give back the money, they wouldn't take it, and so he hung himself.
2. What lies ahead is too precious to be affected by our holding on and looking back   (2 Tim 4:6–8)
3. Our victory in Jesus depends on it   (1 Cor 9:24)  
4. What other choice do we have?   (Luke 9:57–62) — holding to the past just slows us down. Such a person who looks back is not fit for the kingdom of a God.