This quote from 1 Thessalonians 5.24 is like fuel to my soul. It has buoyed me through all sorts of issues: ministry situations, moves, personal problems, an adoption, and on an on. As we waited through the process of adopting our daughter (a long, long process detailed on our family blog: here), I held on and held on and held on and held on and held on to this nugget.
Whenever I sense God's calling to something, it comes with challenges. I wouldn't need Him otherwise. And whenever those challenges come, I run to this verse and let it sustain me. Waiting? Confused? Frustrated? Faithful is He who calls you and He will bring it to pass.