God promises, “My grace is sufficient for you, for my power is made perfect in weakness” ( 2 Cor 12:9 ESV). God will give you all the grace you need for today. However, Jesus also told his disciples, “Do not be anxious for tomorrow; for tomorrow will care for itself. Each day has enough trouble of its own” (Matt 6:34 NASB).
God will give you all the grace you need to do what must be done today. The weaker you become, the more God will increase your grace. We can say with Paul, “When I am weak, then I am strong” (2 Cor 12:10).
When we are weak, however, we still feel weak. Our problems stretch on throughout the foreseeable future with no end in sight. We must remember that God’s mercies are new every morning (Lam 3:22-23), but we only have enough for today. Don’t worry about tomorrow; you have enough to do today. Trust God even when you’re falling apart, and your spirit will be renewed day by day (2 Cor 4:16).