There's a lot we can't do on our own. Especially as Christians. Stuff like overcoming the world (see 1 John 5:4) can only be done with faith in God. 'Faith' is one of those words that's not often defined for us. But here's a pretty clear definition of what faith looks like:
(a) Being certain of victory. Back to 1 John 5:4. You might not be able to see exactly how things will work out in the future, but with God, it always figures out. St. Thérèse de Lisieux said, 'God would never inspire me with desires which cannot be realised; so in spite of my littleness, I can hope to be a saint.'
(b) Being certain of growing to be like God. Faith isn't a one-time event that starts and finishes the moment you become a Christian. We keep growing in our faith, by learning: 'So faith comes from hearing, and hearing through the word of Christ' (Romans 10:17 ESV). And by doing: 'What good is it, my brothers, if someone says he has faith but does not have works' (James 2:14 ESV)?
So what now? So much of this 'faith' business is about being ok about the future. This is not easy... if you're struggling to see past things that worry you, ask God to show you that He is there to help you and to give you faith to get through them.
Soulfood : 2 Chr 32-34, Lk 18:1-17, Ps 119:145-160, Prov 22:14-16