We cannot learn to trust God unless we are willing to experience our own weakness. We might like to think that we can feel strong and trust God at the same time. But this would be like the Pharisee who "praised God" he was "not like other men." He credits God, after all, but he is not willing to admit his need for God. God is the source of his "strength", but he does not know of his own desperate need, a failure that leads to Jesus' condemning words that he did not walk away from that prayer justified.
This same truth is experienced in the midst of our ongoing pilgrimage as well. We might like to reach a plateau of maturity, a level place where godly habits formed in the past guard us from future temptations. In this season, trust becomes an occasional prayer offered out of duty, rather than a plea offered out of need. Our sense of deliverance is rare and rarely acknowledged. We see the further heights of holy risk and godly ambition ahead of us, but the current place of ease is enticing and easy. We would learn greater trust in God, if only it didn't require us to feel weak again.
But we cannot grow in trusting God unless we are willing to experience our own weakness. So we climb upward, we press forward, we move on from the plateau of current ease and into the delightful incline of desperate need. And we learn to trust, again.