“And we know that in all things God works for the good of those who love him, who have been called according to his purpose. 29For those God foreknew he also predestined to be conformed to the likeness of his Son, that he might be the firstborn among many brothers. 30And those he called, he also justified; those he justified, he also glorified. 31What then shall we say in response to this? If God is for us, who can be against us? 32He who did not spare his own Son, but gave him up for us all–how will he not also, along with him, graciously give us all things? 33Who will bring any charge against those whom God has chosen? It is God who justifies. 34Who is he that condemns? Christ Jesus, who died–more than that, who was raised to life–is at the right hand of God and is also interceding for us. 35Who shall separate us from the love of Christ? Shall trouble or hardship or persecution or famine or nakedness or danger or sword? 36As it is written:
“For your sake we face death all day long;
we are considered as sheep to be slaughtered.”
37No, in all these things we are more than conquerors through him who loved us. 38For I am convinced that neither death nor life, neither angels nor demons, neither the present nor the future, nor any powers, 39neither height nor depth, nor anything else in all creation, will be able to separate us from the love of God that is in Christ Jesus our Lord.”
Romans 8:28-39 NIV1984
Christ Jesus, who died–more than that, who was raised to life–is at the right hand of God and is also interceding for us- If Jesus is interceding for us and He is at the right hand of God, calling on Mary and other saints who died is unnecessary because it is unbiblical. Why do you think Jesus prescribed to pray to the Father in His name? (John 15:16).
Verses 38 & 39 connects with John 10:28-29.
If you happen to be hit with thoughts of doubting/questioning your salvation from time to time, put on your helmet of salvation (Ephesians 6:17). Remember that very day you called on Jesus Christ to save you. You are part of the bride of Christ. Whom God has joined to Himself, no demon in hell can separate.