1 Thessalonians 1:3 says that love labours.
The Greek implies toil, or troublesome labor.
Fatigue, difficulty, persistence.
Consider a loving person: do they not work hard? Or a mother! She toils and wearies herself for her children! This is the Biblical example –
For ye remember, brethren, our labour and travail: for labouring night and day, because we would not be chargeable unto any of you, we preached unto you the gospel of God. 1Thessalonians 2:9
Salute Tryphena and Tryphosa, who labour in the Lord. Salute the beloved Persis, which laboured much in the Lord. Romans 16:12
For God is not unrighteous to forget your work and labour of love, which ye have shewed toward his name, in that ye have ministered to the saints, and do minister. Hebrews 6:10
It is a very simple equation. Faith works by love -
Galatians 5:6 - For in Jesus Christ neither circumcision availeth any thing, nor uncircumcision; but faith which worketh by love.