"The Spirit itself beareth witness with our spirit, that we are the children of God:" (Romans 8: 16)
What does the Spirit of God do for us?
More than just healing our bodies or our finances, He convicts us of righteousness:
"8And when he is come, he will reprove the world of sin, and of righteousness, and of judgment: 9Of sin, because they believe not on me; 10Of righteousness, because I go to my Father, and ye see me no more; 11Of judgment, because the prince of this world is judged." (John 16: 8-11)
"Of righteousness, because I go to my Father -- and ye see me no more."
Jesus lives in us today because of His Spirit, and He acts as a witness on our behalf reminding us that He has made us righteous:
"For he hath made him to be sin for us, who knew no sin; that we might be made the righteousness of God in him." (2 Corinthians 5: 21)
Now, righteousness is more than a one-time gift, but a gift which we keep on receiving:
"For if by one man's offence death reigned by one; much more they which receive abundance of grace and of the gift of righteousness shall reign in life by one, Jesus Christ." (Romans 5: 17)
We keep on receiving this gift of righteousness, even if our feelings and our thoughts scream otherwise.
We are made righteous by the blood of Jesus:
"Much more then, being now justified by his blood, we shall be saved from wrath through him." (Romans 5: 9)
Since we are righteous, we know that we are God's children:
"For ye have not received the spirit of bondage again to fear; but ye have received the Spirit of adoption, whereby we cry, Abba, Father." (Romans 8: 15)
"And because ye are sons, God hath sent forth the Spirit of his Son into your hearts, crying, Abba, Father." (Galatians 4: 6)
The Holy Spirit is there to witness to you, whether in good season or bad, whether you are struggling or succeeding, that you are a child of God in Christ.