He did this that He might clearly demonstrate through the ages to come the immeasurable (limitless, surpassing) riches of His free grace (His unmerited favor) in [His] kindness and goodness of heart toward us in Christ Jesus.
Our heavenly Father demonstrated His goodness toward us through what Christ has done for us. This is grace revealed, for Jesus is that grace. How good is our God? So good that He has given us what we did not deserve. This influence of grace on the heart of man is what leads him away from ungodliness and to our God. Grace is heavens help that we receive, undeserved, and not earned. Grace is what empowers us to live free from sin. It empowers us to be partakers of all we have in Christ Jesus.
Scripture teaches us that there is more grace to be received from God once we are born again. James tells us God resists the proud but gives more grace to the humble. The very next verse tells us how to walk in humility. Submit to God, resist the devil, and he will flee from you. Simply put, do what God says in His Word and you are submitting to Him and receive more grace. When you do you are resisting the devil.
Titus 2:10-11 tells us His grace appeared to all men, teaching us to deny all ungodliness and worldly lust, and to live a godly life. The grace that appeared to all men was Jesus. So as you submit to God, following after Jesus who is the Word made flesh, you overcome anything the devil throws at you. So don’t live in pride choosing your own way. Submit to God and receive even more grace, and experience the goodness of your God.