We must never allow our own sinfulness to become the focus of our faith. That is a sure path to trouble. Instead, we must focus intently on Christ as Savior - particularly in relation to these questions:
Focus on these things. Consider each one in detail. The questions appear simple, but the answers are gloriously complex (and totally encouraging). Explore them. Chew on them. Revel in them. Each will lead you to the Gospel as the power of God for all who believe!