The prayer of the father in the gospel today, 'I do believe; help my unbelief!' (Mark 9:24) is not really an expression of doubt. If we know well enough that Jesus is the remedy for our unbelief so as to cry out to him for help, then we already have all the faith we will ever need.
Whatever our doubts or sins or even unbelief, all we really lack is the willingness to consent to the grace that God has already delighted to give us, to surrender to being the saints we were created to be in the first place.
When I was younger I would pray for strength in temptation and for the courage to face the challenges of being a Christian. Now I realize that these graces are already here; it's not that strength and courage are spiritual commodities that have to be squeezed out of a stingy deity. The problem is that that my I'm still too stiff-necked and hard of heart to receive them.
Nowadays, at my better moments, I don't pray for strength in temptation. I pray in thanksgiving to God for finding me worthy of sufferings by which I may show my love for him and at least present him with a token penance for all of my negligence, infidelity, and sin. I don't pray for the courage to live the Christian life, but for the willingness to surrender to the Life who is Christ living in me.
I am willing, Lord, help my unwillingness.