Paul said, "I can do all things through Christ who strengthens me"
(Phil. 4:13).
Some don’t become Christians because they think they won't be able
to remain faithful. Others, for the same reason, give up in
despair. Jesus would say, "O ye of little faith." The Lord gives
strength and help. To think otherwise is to distrust God.
Christians are kept by the power of God through faith (1 Pet. 1:5).
God commands nothing unreasonable (Rom. 12:1), nor does He
demand too much (1 John 5:3). He knows we will not be perfect
(1 John 1:8-9), but He wants us to try.
To help see this point, one could say that the Christian life is like a
person driving their car home on a dark and treacherous night.
They can't see all the way home before they start, neither can they
see every curve, dangerous place, or the on-coming traffic from the
beginning, but they start. They will deal with those things as they
come to them, and with the blessing of God, get home safely. Get
the point?