I have been crucified with Christ, I no longer live but Christ lives in me. The life I live in the body I live by faith in the Son of God, Who loved me and gave Himself for me. My old self has been crucified with Christ. It is no longer I who live, but Christ lives in me. So I live in this earthly body by trusting in the Son of God, who loved me and gave himself for me. Gal 2:20 (NLT)
Its clear to see that Paul came to a place were he realised that they was nothing he can do in his own ability but it was only by Gods grace that he could accomplish what ever was before him. I think we need to come to place were we allow the Lord to lead us. Many times I find my self trying to do something for the Lord in my own strength I get frustrated and tired but one thing when we are led by the Lord they is a peace and a rest in our hearts and they is no pressure. Thats why we need to come to a place were we realise that we are unable but Enabled by His Grace, this is our only security and strength.