If your walk in faith is strong, then you can trust your heart because if God doesn't want you to be with that person He will make it clear to you. But, if your walk with God is weak, then you must strengthen your walk (be more obedient, thankful and prayerful) before entering any relationship. God bless.
"Keep this Book of the Law always on your lips; meditate on it day and night, so that you may be careful to do everything written in it. Then you will be prosperous and successful. Have I not commanded you? Be strong and courageous. Do not be afraid; do not be discouraged, for the LORD your God will be with you wherever you go.”
(Joshua 1:8-9 NIV)
"So do not fear, for I am with you; do not be dismayed, for I am your God. I will strengthen you and help you; I will uphold you with my righteous right hand."
(Isaiah 41:10 NIV)