The only problem you have is unbelief.
If you are born again of the imperishable seed which is the living and enduring Word of God, you are one Spirit with the Lord. [1 Peter 1:23, 1 Corinthians 6:17].
You are an heir of God and a fellow heir with Christ...all things belong to you and you belong to Christ and Christ belongs to God. [Romans 8:17, 1 Corinthians 3:21-23]
The Father has chosen gladly to give you the kingdom and He has given you all things richly to enjoy. [Luke 12:32, 1 Timothy 6:17]
So what's the problem? Why are Christians sick, poor and struggling?
Either the Word is true or it's not.
'So we see that they were not able to enter because of unbelief.Therefore, let us fear if, while a promise remains of entering His rest, any one of you may seem to have come short of it.'For indeed we have had good news preached to us, just as they also; but THE WORD THEY HEARD DID NOT PROFIT THEM, because it was NOT UNITED BY FAITH in those who heard.'...and those who formerly had good news preached to them failed to enter because of disobedience...' [Hebrews 3:19-4:2,6]
Israel did not enter into God's best will because of unbelief, period.
Their father, Abraham, was a different story. He received God's promise because he did not waver in unbelief.
'Without becoming weak in faith he contemplated his own body, now as good as dead since he was about a hundred years old, and the deadness of Sarah's womb; yet, with respect to the promise of God, he did not WAVER IN UNBELIEF but grew strong in faith, giving glory to God, and being fully assured that what God had promised, He was able also to perform.' [Romans 4:19-21]
Jesus told us that we could move mountains by the tiniest portion of faith...and since we're one Spirit with Him, we have His faith. Please not that He put no restriction of any kind on this promise but one...
'And Jesus answered saying to them, "Have faith in God. Truly I say to you, whoever says to this mountain, 'Be taken up and cast into the sea,' and DOES NOT DOUBT IN HIS HEART, but believes that what he says is going to happen, it will be granted him. "Therefore I say to you, all things for which you pray and ask, believe that you have received them, and they will be granted you.' [Mark 11:22-24
There's only one problem, and it's not the devil...he is already defeated.
It's unbelief. And it is sin.
How do we get rid of sin? Repent...turn away from it. Confess it and lay it aside. 'If we confess our sins, He is faithful and righteous to forgive us our sins and to cleanse us from all unrighteousness.' [1 John 1:9]'Therefore, since we have so great a cloud of witnesses surrounding us, let us also LAY ASIDE every encumbrance and the sin which so easily entangles us, and let us run with endurance the race that is set before us, fixing our eyes on Jesus, the author and perfecter of faith, who for the joy set before Him endured the cross, despising the shame, and has sat down at the right hand of the throne of God.' [Hebrews 12:1,2]
Think about it.