Answer:
First, remember this verse:
Romans 8:28 And we know that all things work together for good to them that love God, to them who are the called according to his purpose.
Also remember that when Jesus touched a leper Jesus did not become unlean but the leper became clean. So as you read below in many instances we find a Christian solution took over a pagan date and was seen as a victory over the pagan day for Christ. Since we are celebrating the birth of Jesus Christ and not the sun god festival I too see it as a VICTORY over something the enemy would want to claim (Dec 25) as bad.
One of the fastest growing churches in my own area is situated on a piece of land Anton Levay once cursed (Anton Levay was the head of the Satanic church for years) and claimed for the devil. Today a church of 3,000 sits on that land and there is revival going on. The name of the church is VICTORY Christian Center. Again, instead of saying this was the devils ground the church took it over and said this is God’s ground. The devil is a liar and a thief and has claim to nothing.
As far as churches having people dress like Santa, it is probably in good fun. Remember the red hat is a symbol of Christ’s blood that covers us.