Confidence

"My voice You shall hear in the morning, O Lord; in the morning I will direct it to You, and I will look up. For You are not a God who takes pleasure in wickedness, nor shall evil dwell with You." Psalm 5.3-4

How Great You are, O God!

That bends to hear the voice of the most miserable sinner when he pleads honestly. And if He acts like this with the undeserving, imagine those who walk according to Your righteousness.

TENDER MERCIES

"Have mercy upon me, O God, according to Your loving kindness, according to the multitude of Your tender mercies, blot out my transgressions."     Psalm 51.1

Every sincere prayer has an immediate answer. Especially when it's from a sinner who is repentant. Look at David, for example, who sinned greatly and God still forgave him. The same is true for you too. 
The Secret: sincerity and faith.

BY FAITH

"Now the just shall live by faith; but if anyone draws back, My soul has no pleasure in him."    Hebrews 10:38

First of all, no one is just. But when a sinner becomes DEPENDENT on the Lord, there is faith. This faith is exactly what makes him just, pure and godly to come before Him. 
But, if the just, pure and godly person stops being dependent on Him, then there will no longer be faith.
As a consequence, he will go back to being a lost sinner.