Bad habits must be changed with determination and God's help. It's in the Bible, I John 3:9, TLB. "The person who has been born into God's family does not make a practice of sinning, because now God's life is in him; so he can't keep on sinning, for this new life has been born into him and controls him—he has been born again."
Bad habits deserve no mercy. It's in the Bible, Deuteronomy 12:2-3, TLB. "You must destroy all the heathen altars wherever you find them—high in the mountains, up in the hills, or under the trees. Break the altars, smash the obelisks, burn the shameful images, cut down the metal idols, and leave nothing even to remind you of them!"
Fill your life with good habits. It's in the Bible, Titus 2:7, NKJV. "In all things showing yourself to be a pattern of good works; in doctrine showing integrity, reverence, incorruptibility."
Form the habit of focusing your thoughts on good things. It's in the Bible, Philippians 4:8, TLB. "Fix your thoughts on what is true and good and right. Think about things that are pure and lovely, and dwell on the fine, good things in others. Think about all you can praise God for and be glad about.
What good habits can we start and maintain? Tithing is an excellent habit to develop. It's in the Bible, Deuteronomy 14:22, TLB. "You must tithe all of your crops every year."
Jesus modeled a habit of worship we should imitate. It's in the Bible, Luke 4:16, NIV. "He went to Nazareth, where He had been brought up, and on the Sabbath day He went into the synagogue, as was his custom. And He stood up to read."
Prayer is a valuable habit. It's in the Bible, Matthew 6:5, NIV. "And when you pray, do not be like the hypocrites, for they love to pray standing in the synagogues and on the street corners to be seen by men. I tell you the truth, they have received their reward in full."