At first glance, it might appear the two questions are basically the same. But upon closer examination, the questions illustrate a crucial distinction. In the first case, praying is incidental to smoking, which is the main focus of the actor. And, of course, you can certainly pray while you are smoking. In the second case, praying is central. At those times specifically devoted to prayer, smoking is probably inappropriate because it takes the focus away from the main purpose, which is prayer.
When the Bible encourages us to pray without ceasing (I Thess 5:17), it is referring to an attitude or mindset, not a time set aside especially for prayer. Keith Green captured this in his song “Make My Life A Prayer to You”:
Make my life a prayer to you
I wanna do what you want me to
No empty words and no white lies
No token prayers no compromise
But is the former (attitude) to replace the latter (a time and place of prayer)? The Bible would teach us otherwise. Most of the references to prayer in the Bible are referring to specific times and places, not an attitude.
Here is just a small sampling:
Matthew 6:6 But thou, when thou prayest, enter into thy closet, and when thou hast shut thy door, pray to thy Father which is in secret; and thy Father which seeth in secret shall reward thee openly.
Matthew 14:23 And when he had sent the multitudes away, he went up into a mountain apart to pray: and when the evening was come, he was there alone.
Matthew 21:13 It is written, My house shall be called the house of prayer; but ye have made it a den of thieves.
Luke 6:12 And it came to pass in those days, that he went out into a mountain to pray, and continued all night in prayer to God.
Few Christians believe an attitude of prayer is to replace times of prayer. However, there have been many who have justified abandoning the corporate worship of God, based upon the same erroneous assumptions concerning worship. As far as I can tell, there is possibly only one passage in the New Testament that says our day-to-day lives are a form of worship.
Romans 12:1 I beseech you therefore, brethren, by the mercies of God, that ye present your bodies a living sacrifice, holy, acceptable unto God, which is your reasonable service (KJV).
Other translations replace the words “reasonable service” with “spiritual worship”. Regardless of which is the best translation, it is quite clear that worship (and praise) in Scripture is usually referring to specific acts showing devotion to God wherein His Name is glorified by the giving of gifts, singing praises to God, or bowing down.
Here are few examples:
Genesis 22:5 And Abraham said unto his young men, Abide ye here with the ass; and I and the lad will go yonder and worship, and come again to you.
Genesis 24:26 And the man bowed down his head, and worshipped the LORD.
Judges 5:3 Hear, O ye kings; give ear, O ye princes; I, even I, will sing unto the LORD; I will sing praise to the LORD God of Israel.
Psalm 5:7 But as for me, I will come [into] thy house in the multitude of thy mercy: [and] in thy fear will I worship toward thy holy temple.
Psalm 7:17 I will praise the LORD according to his righteousness: and will sing praise to the name of the LORD most high.
Isaiah 27:13 And it shall come to pass in that day, that the great trumpet shall be blown, and they shall come which were ready to perish in the land of Assyria, and the outcasts in the land of Egypt, and shall worship the LORD in the holy mount at Jerusalem.
Matthew 2:1-2 Now when Jesus was born in Bethlehem of Judaea in the days of Herod the king, behold, there came wise men from the east to Jerusalem, Saying, Where is he that is born King of the Jews? for we have seen his star in the east, and are come to worship him.
John 4:23-24 But the hour cometh, and now is, when the true worshippers shall worship the Father in spirit and in truth: for the Father seeketh such to worship him. God is a Spirit: and they that worship him must worship him in spirit and in truth.
Colossians 3:16 Let the word of Christ dwell in you richly in all wisdom; teaching and admonishing one another in psalms and hymns and spiritual songs, singing with grace in your hearts to the Lord.
Hebrews 2:12 I will declare thy name unto my brethren, in the midst of the church will I sing praise unto thee.
I included these last three verses to demonstrate there is no contradiction between the individual worshipping God at any time and any place (John 4) and the corporate worship when the saints gather together (Heb 2, Col 3). There is no excuse for using the one to neglect the other. God commands both.
 In a recent post about churches canceling Sunday evening services for the Super Bowl or holding Super Bowl parties instead, many defenders of these practices didn’t make the argument that one service is enough, or that there is no Sabbath today, but rather they said that going to a sports bar to watch football is worship – everything the Christian does in obedience is worship: brushing your teeth, taking out the trash, etc. Those arguments inspired this post.