1 Corinthians 1:8 amp

And He will establish you to the end (keep you steadfast, give you strength, and guarantee your vindication; He will be your warrant against all accusation or indictment so that you will be) guiltless and irreproachable in the day of our Lord Jesus Christ.  

On those days when we are down and discouraged, we need to remind ourselves what Jesus has done for us.  The Lord, for the believer, promises to establish us and build us up in strength.  He promises to intercede on our behalf when we pray for help and keep us out of danger.  Jesus became our sin to keep us guiltless and irreproachable.