Fathers, don't be a false teacher to your children.
There is no other person who will have a bigger impact on your child's beliefs and values than you. Everything you do and everything you say shapes how they view the world and what they believe. If you let influence into the home that should not be there, then your children are not likely to question it's presence. You must be vigilant and stand your ground against the attacks of the accuser.
You are the watchman on the wall guarding their spiritual wellbeing. An entire stronghold an be lost to the enemy if the watchman doesn't do his job. A single gate left unwatched and undefended can lead to the downfall of many.
We can not effectively guard against threats that we fail to identify as such. The world is constantly throwing ideas and stories at us that are contrary to what God has decreed as good and righteous. Whether it is a direct contradiction or a subtle nudge we must recognize the threat and work to guard against it. I know I fail in this more than I care to admit. I know that, like Lot, I have allowed more ungodly influence into my household than I should have. That does not have to be the end of my story though. My God is a God of redemption. He is a God of regeneration.
Look at Paul. He was a murderer of Christians. He went from city to city seeking them out to kill them. If anyone would have been excluded from God's grace it would have been him. Instead, God used him powerfully to bring the gentiles into the body of Christ.
Look at Peter. He was with Jesus every day for years. He walked on water to meet him and he recognized Jesus as "the Christ, the Son of the living God” before anyone else. Peter swore he would never turn away, and yet, when Jesus faced His darkest hour, when He stood unjustly accused and in danger for His life, Peter turned away and left him. Jesus came back after He had risen and restored Peter. Jesus redeemed what was lost and renewed Peter's faith and purpose.
Jesus entrusted the Church to men like this, broken and unworthy but redeemed and restored. If you have failed your family, it is not too late to seek God and his grace. Put on the full armor of God and stand in the gap for your family. There is no one else who is better able to do so.
"Train up a child in the way he should go,
Even when he is old he will not depart from it. "
-Proverbs 22:6
"Finally, be strong in the Lord and in the strength of His might. Put on the full armor of God, so that you will be able to stand firm against the schemes of the devil. For our struggle is not against flesh and blood, but against the rulers, against the powers, against the world forces of this darkness, against the spiritual forces of wickedness in the heavenly places. Therefore, take up the full armor of God, so that you will be able to resist in the evil day, and having done everything, to stand firm. Stand firm therefore, having girded your loins with truth, and having put on the breastplate of righteousness, and having shod your feet with the preparation of the gospel of peace; in addition to all, taking up the shield of faith with which you will be able to extinguish all the flaming arrows of the evil one. And take the helmet of salvation, and the sword of the Spirit, which is the word of God. "
-Ephesians 6:10-17