Jesus did not call us because of our righteousness or gifting. He called us when we were dead in our sins (Eph. 2.1) and blinded by the god of this world (2 Cor. 4.4). He called us when all we had was need.
And now that we are his disciples, all we redeemed sinners still really have is our need of his him. He is the Vine, and we are the branches; apart from him we can do nothing (John 15.5). He supplies us with the Spirit (Gal. 3.5)so that we serve in only the strength and grace that he supplies (I Peter 4.11).
Jon Bloom, Not By Sight, p.196