This sentence also emphasizes the other party's commitment and determination to you. He/she will make every effort to maintain the feelings between you and make you feel happy and satisfied. He/she wants to share all the wonderful moments in life with you and create your own happiness together.
Generally speaking, this sentence expresses the sincere feelings of the other person for you and his/her commitment to the future. Only when he/she is with you can his/her life be truly full of happiness and happiness.