In Romans 8:33-35 Paul asks a series of questions where the answer to each is an emphatic "no one!" (vs 37-39).  I will summarize them here:

• If God is for us, who is against us?  No one!
• Who will bring a charge against God's elect?  No one!
• Who will condemn?  No one!
• Who will separate us from the love of Christ?  No one!

Why?  Because "we know that God causes all things to work together for good to those who love God, to those who are called according to His purpose. For those whom He foreknew, He also predestined to become conformed to the image of His Son, so that He would be the firstborn among many brethren; and these whom He predestined, He also called; and these whom He called, He also justified; and these whom He justified, He also glorified." (Romans 8:28-30)

Christ died for his own and no one can separate us from the love of Christ.  God justifies and no one can reverse God's justification.  I thank God that He is the author and finisher of my faith (Hebrews 12:2).