There can be no substantiated doubts about God’s love for us. Any struggle or experience we may have of doubts ought to be immediately reconciled and cancelled out by reflecting upon the fact that God chose to send His Son to die for us while we were sinners. This ought to be sufficient and inscrutable evidence of the depths of His love for us.
Romans 5:1-2, 5-8
1 Brothers and sisters: Since we have been justified by faith, we have peace with God through our Lord Jesus Christ, 2 through whom we have gained access by faith to this grace in which we stand, and we boast in hope of the glory of God. 5 And hope does not disappoint, because the love of God has been poured out into our hearts through the Holy Spirit that has been given to us. 6 For Christ, while we were still helpless, yet died at the appointed time for the ungodly. 7 Indeed, only with difficulty does one die for a just person, though perhaps for a good person one might even find courage to die. 8 But God proves his love for us in that while we were still sinners Christ died for us.