"If you openly declare that Jesus is Lord and believe in your heart that God raised him from the dead, you will be saved. For it is by believing in your heart that you are made right with God, and it is by openly declaring your faith that you are saved."

(Romans 10.9-10 NLT)

A "declaration" has no impact and is worthless without actions consistent with the "declaration" and all the implications. A "declaration" is a commitment.

If I utter with my mouth, but I do not follow through with my commitment, then will God recognise such "declaration"?

Dear God,
please help me believe fully and sincerely
and make me right with you

~

See:
Law and faith (3)
Law and faith (4)
Total abandonment