Romans 7:18

18 For I know that in me, that is, in my flesh, dwells no good thing. For desire is present with me, but I don't find it doing that which is good. 

2 Corinthians 12:9

9 He has said to me, "My grace is sufficient for you, for my power is made perfect in weakness." Most gladly therefore I will rather glory in my weaknesses, that the power of Christ may rest on me.

Philippians 4:13

13 I can do all things through Christ, who strengthens me.