'Fervently' in the Bible

Now at the time when Silas and Timothy came down from Macedonia, Paul was preaching fervently and was solemnly telling the Jews that Jesus is the Christ.

Now that, through your obedience to the truth, you have purified your souls for cherishing sincere brotherly love, you must love another heartily and fervently.

Above all continue to love one another fervently, for love throws a veil over a multitude of faults.