Transformation is effortless, but it is the product of believing, and it may take massive amounts of effort to persuade your heart to believe. Your new heart wants to believe. It knows how to believe. It's spiritually genetically encoded to believe. But the competing thoughts in your mind might rob your heart from being fully persuaded.
The remedy to doubt and unbelief is to seed your heart with the Word of God and not allow it to be plucked out or choked by cares, lust, and money issues.
Once you seed your heart with God's Word, and you are standing to give it time to grow and bear fruit, you have to push away doubt and fear.