"If You heal my body of disease, then I will serve You all of my life."
"If You pay my bills, then I will tithe."
"If You give me peace, then I will go and be a peacemaker."
Japhthah's "If You, then I" statement is written in Judges 11:30-32.
"And Jephthah made a vow to the Lord and said, If You will indeed give the Ammonites into my hand,
Then whatever or whoever comes forth from the doors of my house to meet me when I return in peace from the Ammonites, it shall be the Lord's, and I will offer it or him up as a burnt offering.
Then Jephthah crossed over to the Ammonites to fight with them, and the Lord gave them into his hand."
This "passion without holy sense" vow ended poorly. Japhthah's beloved daughter came through the doors of his house to meet him. OUCH!!! See Judges 11:34-40.
Let's be careful not to place conditions on our obedience, service, and devotion to the Lord. Instead of "If You, then I" statements, let's use "Because I trust You, I will" declarations.
"Because I trust You heal my body of disease (even if the disease still manifests), I will serve You all of my life."
"Because I trust You to help me pay my bills this month, I will tithe."
"Because I trust You have given me peace, I will go and spread that peace to others."
These statements declare the character of God and how we should respond to that character.
Maybe Jephthah should have said,
"And Jephthah spoke to the Lord and said, Because I trust You will empower me to defeat Israel's enemies, the Ammonites, whatever or whoever comes forth from the doors of my house to meet me when I return in peace from the Ammonites, I shall consecrate to You, and I will bless and sing Your praises with him."